From 18990b4e4f7c8423e2e65184824ae96f9f3656fa Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 13:45:57 +0200
Subject: [PATCH 01/17] adding NegotiateAppVersion implementation and tests

---
 modules/apps/27-interchain-accounts/module.go | 18 ++++-
 .../27-interchain-accounts/module_test.go     | 70 +++++++++++++++++++
 2 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 modules/apps/27-interchain-accounts/module_test.go

diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index 740eea4ad6b..f6f075a7f03 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -255,6 +255,20 @@ func (am AppModule) OnTimeoutPacket(
 	return nil
 }
 
-func (am AppModule) NegotiateAppVersion(ctx sdk.Context, order channeltypes.Order, connectionID, portID string, counterparty channeltypes.Counterparty, proposedVersion string) (string, error) {
-	return "", nil
+// NegotiateAppVersion implements the IBCModule interface
+func (am AppModule) NegotiateAppVersion(
+	ctx sdk.Context,
+	order channeltypes.Order,
+	connectionID string,
+	portID string,
+	counterparty channeltypes.Counterparty,
+	proposedVersion string,
+) (string, error) {
+	if proposedVersion != types.Version {
+		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.Version, proposedVersion)
+	}
+
+	addr := types.GenerateAddress(counterparty.PortId)
+
+	return fmt.Sprintf("%s-%s", types.Version, addr), nil
 }
diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
new file mode 100644
index 00000000000..db73022ba18
--- /dev/null
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -0,0 +1,70 @@
+package interchain_accounts_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+
+	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
+	channeltypes "github.com/cosmos/ibc-go/modules/core/04-channel/types"
+	ibctesting "github.com/cosmos/ibc-go/testing"
+)
+
+type InterchainAccountsTestSuite struct {
+	suite.Suite
+
+	coordinator *ibctesting.Coordinator
+
+	// testing chains used for convenience and readability
+	chainA *ibctesting.TestChain
+	chainB *ibctesting.TestChain
+	chainC *ibctesting.TestChain
+}
+
+func (suite *InterchainAccountsTestSuite) SetupTest() {
+	suite.coordinator = ibctesting.NewCoordinator(suite.T(), 3)
+	suite.chainA = suite.coordinator.GetChain(ibctesting.GetChainID(0))
+	suite.chainB = suite.coordinator.GetChain(ibctesting.GetChainID(1))
+	suite.chainC = suite.coordinator.GetChain(ibctesting.GetChainID(2))
+}
+
+func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
+	path := ibctesting.NewPath(chainA, chainB)
+	path.EndpointA.ChannelConfig.PortID = types.PortID
+	path.EndpointB.ChannelConfig.PortID = types.PortID
+	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
+	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
+	path.EndpointA.ChannelConfig.Version = types.Version
+	path.EndpointB.ChannelConfig.Version = types.Version
+
+	return path
+}
+
+func TestICATestSuite(t *testing.T) {
+	suite.Run(t, new(InterchainAccountsTestSuite))
+}
+
+func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
+	suite.SetupTest()
+	path := NewICAPath(suite.chainA, suite.chainB)
+	suite.coordinator.SetupConnections(path)
+
+	module, _, err := suite.chainA.App.GetIBCKeeper().PortKeeper.LookupModuleByPort(suite.chainA.GetContext(), types.PortID)
+	suite.Require().NoError(err)
+
+	cbs, ok := suite.chainA.App.GetIBCKeeper().Router.GetRoute(module)
+	suite.Require().True(ok)
+
+	counterpartyPortID, err := types.GeneratePortID("testing", path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
+	suite.Require().NoError(err)
+
+	counterparty := &channeltypes.Counterparty{
+		PortId:    counterpartyPortID,
+		ChannelId: path.EndpointB.ChannelID,
+	}
+
+	version, err := cbs.NegotiateAppVersion(suite.chainA.GetContext(), channeltypes.ORDERED, path.EndpointA.ConnectionID, types.PortID, *counterparty, types.Version)
+	suite.Require().NoError(err)
+	suite.Require().True(strings.Contains(version, types.Version))
+}

From 49e290165313085fa5ad895cbc8f6d24c8292d16 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 13:46:41 +0200
Subject: [PATCH 02/17] updating GenerateAddress to return sdk.AccAddress,
 fixing tests

---
 .../27-interchain-accounts/types/account.go   |  6 +-
 .../types/account_test.go                     | 61 +++++++++++++------
 2 files changed, 47 insertions(+), 20 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/types/account.go b/modules/apps/27-interchain-accounts/types/account.go
index 93f8b18e9a4..dc41ffd64fe 100644
--- a/modules/apps/27-interchain-accounts/types/account.go
+++ b/modules/apps/27-interchain-accounts/types/account.go
@@ -20,9 +20,9 @@ const (
 	ICAPrefix string = "ics-27"
 )
 
-// GenerateAddress returns a truncated SHA256 hash using the provided port string
-func GenerateAddress(port string) []byte {
-	return tmhash.SumTruncated([]byte(port))
+// GenerateAddress returns an sdk.AccAddress using a truncated SHA256 hash of the provided port identifier
+func GenerateAddress(portID string) sdk.AccAddress {
+	return sdk.AccAddress(tmhash.SumTruncated([]byte(portID)))
 }
 
 // GeneratePortID generates the portID for a specific owner
diff --git a/modules/apps/27-interchain-accounts/types/account_test.go b/modules/apps/27-interchain-accounts/types/account_test.go
index 15bc23eb3e8..e72241fc1e0 100644
--- a/modules/apps/27-interchain-accounts/types/account_test.go
+++ b/modules/apps/27-interchain-accounts/types/account_test.go
@@ -1,6 +1,7 @@
 package types_test
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
@@ -32,7 +33,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = types.Version
+	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
 
 	return path
 }
@@ -44,27 +45,53 @@ func TestTypesTestSuite(t *testing.T) {
 func (suite *TypesTestSuite) TestGeneratePortID() {
 	var (
 		path  *ibctesting.Path
-		owner string
+		owner = "testing"
 	)
-	var testCases = []struct {
+
+	testCases := []struct {
 		name     string
 		malleate func()
 		expValue string
 		expPass  bool
 	}{
-		{"success", func() {}, "ics-27-0-0-owner123", true},
-		{"success with non matching connection sequences", func() {
-			path.EndpointA.ConnectionID = "connection-1"
-		}, "ics-27-1-0-owner123", true},
-		{"invalid owner address", func() {
-			owner = "    "
-		}, "", false},
-		{"invalid connectionID", func() {
-			path.EndpointA.ConnectionID = "connection"
-		}, "", false},
-		{"invalid counterparty connectionID", func() {
-			path.EndpointB.ConnectionID = "connection"
-		}, "", false},
+		{
+			"success",
+			func() {},
+			"ics-27-0-0-testing",
+			true,
+		},
+		{
+			"success with non matching connection sequences",
+			func() {
+				path.EndpointA.ConnectionID = "connection-1"
+			},
+			"ics-27-1-0-testing",
+			true,
+		},
+		{
+			"invalid owner address",
+			func() {
+				owner = "    "
+			},
+			"",
+			false,
+		},
+		{
+			"invalid connectionID",
+			func() {
+				path.EndpointA.ConnectionID = "connection"
+			},
+			"",
+			false,
+		},
+		{
+			"invalid counterparty connectionID",
+			func() {
+				path.EndpointB.ConnectionID = "connection"
+			},
+			"",
+			false,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -73,11 +100,11 @@ func (suite *TypesTestSuite) TestGeneratePortID() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
 			suite.coordinator.Setup(path)
-			owner = "owner123" // must be explicitly changed
 
 			tc.malleate()
 
 			portID, err := types.GeneratePortID(owner, path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
+
 			if tc.expPass {
 				suite.Require().NoError(err, tc.name)
 				suite.Require().Equal(tc.expValue, portID)

From 1f73b16f75f46c6aa0aa8073e36c7c8b44d98324 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 13:47:33 +0200
Subject: [PATCH 03/17] updating ica handshake flow to parse address from
 version string, fixing associated tests

---
 .../27-interchain-accounts/keeper/account.go  | 19 +++++++-----
 .../keeper/handshake.go                       | 31 ++++++++++++++-----
 .../keeper/handshake_test.go                  |  4 ++-
 .../keeper/keeper_test.go                     |  3 +-
 4 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/keeper/account.go b/modules/apps/27-interchain-accounts/keeper/account.go
index 43e3bc4b143..176e6545c94 100644
--- a/modules/apps/27-interchain-accounts/keeper/account.go
+++ b/modules/apps/27-interchain-accounts/keeper/account.go
@@ -40,23 +40,28 @@ func (k Keeper) InitInterchainAccount(ctx sdk.Context, connectionID, counterpart
 	return nil
 }
 
-// Register interchain account if it has not already been created
-func (k Keeper) RegisterInterchainAccount(ctx sdk.Context, portID string) {
-	address := types.GenerateAddress(portID)
+// RegisterInterchainAccount attempts to create a new account using the provided address and stores it in state keyed by the provided port identifier
+// If an account for the provided address already exists this function returns nil
+func (k Keeper) RegisterInterchainAccount(ctx sdk.Context, address, portID string) error {
+	accAddr, err := sdk.AccAddressFromBech32(address)
+	if err != nil {
+		return err
+	}
 
-	account := k.accountKeeper.GetAccount(ctx, address)
-	if account != nil {
-		return
+	if acc := k.accountKeeper.GetAccount(ctx, accAddr); acc != nil {
+		return nil
 	}
 
 	interchainAccount := types.NewInterchainAccount(
-		authtypes.NewBaseAccountWithAddress(address),
+		authtypes.NewBaseAccountWithAddress(accAddr),
 		portID,
 	)
 
 	k.accountKeeper.NewAccount(ctx, interchainAccount)
 	k.accountKeeper.SetAccount(ctx, interchainAccount)
 	k.SetInterchainAccountAddress(ctx, portID, interchainAccount.Address)
+
+	return nil
 }
 
 func (k Keeper) GetInterchainAccount(ctx sdk.Context, addr sdk.AccAddress) (types.InterchainAccount, error) {
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake.go b/modules/apps/27-interchain-accounts/keeper/handshake.go
index e4677b72188..e209e7eb047 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake.go
@@ -1,6 +1,9 @@
 package keeper
 
 import (
+	"fmt"
+	"strings"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
@@ -36,8 +39,9 @@ func (k Keeper) OnChanOpenInit(
 	if counterparty.PortId != types.PortID {
 		return sdkerrors.Wrapf(porttypes.ErrInvalidPort, "counterparty port-id must be '%s', (%s != %s)", types.PortID, counterparty.PortId, types.PortID)
 	}
-	if version != types.Version {
-		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelVersion, "channel version must be '%s' (%s != %s)", types.Version, version, types.Version)
+
+	if !strings.Contains(version, types.Version) {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid version: %s, expected %s", version, types.Version)
 	}
 
 	existingChannelID, found := k.GetActiveChannel(ctx, portID)
@@ -71,10 +75,12 @@ func (k Keeper) OnChanOpenTry(
 	if order != channeltypes.ORDERED {
 		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelOrdering, "invalid channel ordering: %s, expected %s", order.String(), channeltypes.ORDERED.String())
 	}
-	if version != types.Version {
-		return sdkerrors.Wrapf(types.ErrInvalidVersion, "got: %s, expected %s", version, types.Version)
+
+	if !strings.Contains(version, types.Version) {
+		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid version: %s, expected %s", version, types.Version)
 	}
-	if counterpartyVersion != types.Version {
+
+	if !strings.Contains(counterpartyVersion, types.Version) {
 		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: %s, expected %s", counterpartyVersion, types.Version)
 	}
 
@@ -85,22 +91,33 @@ func (k Keeper) OnChanOpenTry(
 	}
 
 	// Register interchain account if it does not already exist
-	k.RegisterInterchainAccount(ctx, counterparty.PortId)
+	accAddr := strings.TrimPrefix(version, fmt.Sprintf("%s-", types.Version))
+	if err := k.RegisterInterchainAccount(ctx, accAddr, counterparty.PortId); err != nil {
+		return err
+	}
+
 	return nil
 }
 
+// OnChanOpenAck sets the active channel for the interchain account/owner pair
+// and stores the associated interchain account address in state keyed by it's corresponding port identifier
+//
+// Controller Chain
 func (k Keeper) OnChanOpenAck(
 	ctx sdk.Context,
 	portID,
 	channelID string,
 	counterpartyVersion string,
 ) error {
-	if counterpartyVersion != types.Version {
+	if !strings.Contains(counterpartyVersion, types.Version) {
 		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: %s, expected %s", counterpartyVersion, types.Version)
 	}
 
 	k.SetActiveChannel(ctx, portID, channelID)
 
+	accAddr := strings.TrimPrefix(counterpartyVersion, fmt.Sprintf("%s-", types.Version))
+	k.SetInterchainAccountAddress(ctx, portID, accAddr)
+
 	return nil
 }
 
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake_test.go b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
index 35f09372f76..4ab8a2ee27d 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
@@ -1,6 +1,8 @@
 package keeper_test
 
 import (
+	"fmt"
+
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
 
 	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
@@ -158,7 +160,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 				Ordering:       channeltypes.ORDERED,
 				Counterparty:   counterparty,
 				ConnectionHops: []string{path.EndpointB.ConnectionID},
-				Version:        types.Version,
+				Version:        fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing")),
 			}
 
 			chanCap, err = suite.chainB.App.GetScopedIBCKeeper().NewCapability(suite.chainB.GetContext(), host.ChannelCapabilityPath(path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID))
diff --git a/modules/apps/27-interchain-accounts/keeper/keeper_test.go b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
index 7064d6ebc07..a2440c75e18 100644
--- a/modules/apps/27-interchain-accounts/keeper/keeper_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
@@ -1,6 +1,7 @@
 package keeper_test
 
 import (
+	"fmt"
 	"testing"
 
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
@@ -36,7 +37,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = types.Version
+	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
 
 	return path
 }

From b967f085e2b5e9d25b1de4ded90d7abd307e7910 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 14:00:41 +0200
Subject: [PATCH 04/17] updating module_tests

---
 modules/apps/27-interchain-accounts/module_test.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
index db73022ba18..58bf50579fd 100644
--- a/modules/apps/27-interchain-accounts/module_test.go
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -1,6 +1,7 @@
 package interchain_accounts_test
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
@@ -36,7 +37,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = types.Version
+	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
 
 	return path
 }
@@ -50,10 +51,10 @@ func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
 	path := NewICAPath(suite.chainA, suite.chainB)
 	suite.coordinator.SetupConnections(path)
 
-	module, _, err := suite.chainA.App.GetIBCKeeper().PortKeeper.LookupModuleByPort(suite.chainA.GetContext(), types.PortID)
+	module, _, err := suite.chainA.GetSimApp().GetIBCKeeper().PortKeeper.LookupModuleByPort(suite.chainA.GetContext(), types.PortID)
 	suite.Require().NoError(err)
 
-	cbs, ok := suite.chainA.App.GetIBCKeeper().Router.GetRoute(module)
+	cbs, ok := suite.chainA.GetSimApp().GetIBCKeeper().Router.GetRoute(module)
 	suite.Require().True(ok)
 
 	counterpartyPortID, err := types.GeneratePortID("testing", path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
@@ -67,4 +68,5 @@ func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
 	version, err := cbs.NegotiateAppVersion(suite.chainA.GetContext(), channeltypes.ORDERED, path.EndpointA.ConnectionID, types.PortID, *counterparty, types.Version)
 	suite.Require().NoError(err)
 	suite.Require().True(strings.Contains(version, types.Version))
+	suite.Require().True(strings.Contains(version, types.GenerateAddress(counterpartyPortID).String()))
 }

From 52fe314a58002b4bf9e20547c9357598b354a8be Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 14:11:12 +0200
Subject: [PATCH 05/17] derive ica addresses from module account addr

---
 .../27-interchain-accounts/types/account.go   |  7 +++---
 .../apps/27-interchain-accounts/types/keys.go | 24 ++++++++++++-------
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/types/account.go b/modules/apps/27-interchain-accounts/types/account.go
index dc41ffd64fe..d7847b2d3f8 100644
--- a/modules/apps/27-interchain-accounts/types/account.go
+++ b/modules/apps/27-interchain-accounts/types/account.go
@@ -9,9 +9,9 @@ import (
 
 	crypto "github.com/cosmos/cosmos-sdk/crypto/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/address"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
-	"github.com/tendermint/tendermint/crypto/tmhash"
 
 	connectiontypes "github.com/cosmos/ibc-go/modules/core/03-connection/types"
 )
@@ -20,9 +20,10 @@ const (
 	ICAPrefix string = "ics-27"
 )
 
-// GenerateAddress returns an sdk.AccAddress using a truncated SHA256 hash of the provided port identifier
+// GenerateAddress returns an sdk.AccAddress using the provided port identifier and derived from the IBC interchainaccounts module account
 func GenerateAddress(portID string) sdk.AccAddress {
-	return sdk.AccAddress(tmhash.SumTruncated([]byte(portID)))
+	moduleAcc := address.Module(ModuleName, ModuleAccountKey)
+	return sdk.AccAddress(address.Derive(moduleAcc, []byte(portID)))
 }
 
 // GeneratePortID generates the portID for a specific owner
diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index 909813ec46d..07066ea0777 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -6,22 +6,34 @@ const (
 	// ModuleName defines the Interchain Account module name
 	ModuleName = "interchainaccounts"
 
-	// Version defines the current version the IBC tranfer
+	// Version defines the current version the IBC interchainaccounts
 	// module supports
 	Version = "ics27-1"
 
+	// PortID is the default port id that the interchainaccounts module binds to
 	PortID = "ibcaccount"
 
-	StoreKey  = ModuleName
+	// StoreKey is the store key string for IBC interchainaccounts
+	StoreKey = ModuleName
+
+	// RouterKey is the message route for IBC interchainaccounts
 	RouterKey = ModuleName
 
+	// QuerierRoute is the querier route for IBC interchainaccounts
+	QuerierRoute = ModuleName
+)
+
+var (
+	// ModuleAccountKey defines the key used to construct to the IBC interchainaccounts module account address
+	ModuleAccountKey = []byte(ModuleName)
+
 	// Key to store portID in our store
 	PortKey = "portID"
 
-	QuerierRoute = ModuleName
-
 	// MemStoreKey defines the in-memory store key
 	MemStoreKey = "mem_capability"
+
+	KeyPrefixRegisteredAccount = []byte("register")
 )
 
 func KeyActiveChannel(portId string) []byte {
@@ -32,10 +44,6 @@ func KeyOwnerAccount(portId string) []byte {
 	return []byte(fmt.Sprintf("owner/%s", portId))
 }
 
-var (
-	KeyPrefixRegisteredAccount = []byte("register")
-)
-
 func GetIdentifier(portID, channelID string) string {
 	return fmt.Sprintf("%s/%s/", portID, channelID)
 }

From bd66f33c8a0b185a97f8911445af5f5f7b2f6423 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Wed, 15 Sep 2021 18:30:04 +0200
Subject: [PATCH 06/17] removing unused keys

---
 modules/apps/27-interchain-accounts/types/keys.go | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index 07066ea0777..3c1a721d9da 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -29,11 +29,6 @@ var (
 
 	// Key to store portID in our store
 	PortKey = "portID"
-
-	// MemStoreKey defines the in-memory store key
-	MemStoreKey = "mem_capability"
-
-	KeyPrefixRegisteredAccount = []byte("register")
 )
 
 func KeyActiveChannel(portId string) []byte {

From 62e5c393e9bd05703f00f000e93a1a6785ac5f07 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Thu, 16 Sep 2021 15:30:40 +0200
Subject: [PATCH 07/17] adding improved version validation, updating tests

---
 .../27-interchain-accounts/keeper/account.go  | 13 ++----
 .../keeper/account_test.go                    |  4 +-
 .../keeper/handshake.go                       | 30 +++++++-------
 .../keeper/handshake_test.go                  | 21 +++++-----
 .../keeper/keeper_test.go                     | 11 ++++-
 .../keeper/relay_test.go                      |  2 +-
 modules/apps/27-interchain-accounts/module.go |  2 +-
 .../27-interchain-accounts/module_test.go     | 15 ++++---
 .../27-interchain-accounts/types/account.go   | 25 +++++++-----
 .../types/account_test.go                     | 38 +++++++++---------
 .../27-interchain-accounts/types/errors.go    |  6 +--
 .../apps/27-interchain-accounts/types/keys.go | 12 +++---
 .../27-interchain-accounts/types/validate.go  | 40 +++++++++++++++++++
 13 files changed, 137 insertions(+), 82 deletions(-)
 create mode 100644 modules/apps/27-interchain-accounts/types/validate.go

diff --git a/modules/apps/27-interchain-accounts/keeper/account.go b/modules/apps/27-interchain-accounts/keeper/account.go
index 176e6545c94..5f31c3df0c8 100644
--- a/modules/apps/27-interchain-accounts/keeper/account.go
+++ b/modules/apps/27-interchain-accounts/keeper/account.go
@@ -41,15 +41,10 @@ func (k Keeper) InitInterchainAccount(ctx sdk.Context, connectionID, counterpart
 }
 
 // RegisterInterchainAccount attempts to create a new account using the provided address and stores it in state keyed by the provided port identifier
-// If an account for the provided address already exists this function returns nil
-func (k Keeper) RegisterInterchainAccount(ctx sdk.Context, address, portID string) error {
-	accAddr, err := sdk.AccAddressFromBech32(address)
-	if err != nil {
-		return err
-	}
-
+// If an account for the provided address already exists this function returns early (no-op)
+func (k Keeper) RegisterInterchainAccount(ctx sdk.Context, accAddr sdk.AccAddress, portID string) {
 	if acc := k.accountKeeper.GetAccount(ctx, accAddr); acc != nil {
-		return nil
+		return
 	}
 
 	interchainAccount := types.NewInterchainAccount(
@@ -60,8 +55,6 @@ func (k Keeper) RegisterInterchainAccount(ctx sdk.Context, address, portID strin
 	k.accountKeeper.NewAccount(ctx, interchainAccount)
 	k.accountKeeper.SetAccount(ctx, interchainAccount)
 	k.SetInterchainAccountAddress(ctx, portID, interchainAccount.Address)
-
-	return nil
 }
 
 func (k Keeper) GetInterchainAccount(ctx sdk.Context, addr sdk.AccAddress) (types.InterchainAccount, error) {
diff --git a/modules/apps/27-interchain-accounts/keeper/account_test.go b/modules/apps/27-interchain-accounts/keeper/account_test.go
index 3d9cd9bae49..69ac5a5dc87 100644
--- a/modules/apps/27-interchain-accounts/keeper/account_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/account_test.go
@@ -44,8 +44,8 @@ func (suite *KeeperTestSuite) TestInitInterchainAccount() {
 		tc := tc
 
 		suite.Run(tc.name, func() {
-			suite.SetupTest() // reset
-			owner = "owner"   // must be explicitly changed
+			suite.SetupTest()        // reset
+			owner = TestOwnerAddress // must be explicitly changed
 			path = NewICAPath(suite.chainA, suite.chainB)
 			suite.coordinator.SetupConnections(path)
 
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake.go b/modules/apps/27-interchain-accounts/keeper/handshake.go
index e209e7eb047..e6d0b32ca8d 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake.go
@@ -1,7 +1,6 @@
 package keeper
 
 import (
-	"fmt"
 	"strings"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -40,8 +39,8 @@ func (k Keeper) OnChanOpenInit(
 		return sdkerrors.Wrapf(porttypes.ErrInvalidPort, "counterparty port-id must be '%s', (%s != %s)", types.PortID, counterparty.PortId, types.PortID)
 	}
 
-	if !strings.Contains(version, types.Version) {
-		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid version: %s, expected %s", version, types.Version)
+	if err := types.ValidateVersion(version); err != nil {
+		return err
 	}
 
 	existingChannelID, found := k.GetActiveChannel(ctx, portID)
@@ -76,12 +75,12 @@ func (k Keeper) OnChanOpenTry(
 		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelOrdering, "invalid channel ordering: %s, expected %s", order.String(), channeltypes.ORDERED.String())
 	}
 
-	if !strings.Contains(version, types.Version) {
-		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid version: %s, expected %s", version, types.Version)
+	if err := types.ValidateVersion(version); err != nil {
+		return err
 	}
 
-	if !strings.Contains(counterpartyVersion, types.Version) {
-		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: %s, expected %s", counterpartyVersion, types.Version)
+	if err := types.ValidateVersion(counterpartyVersion); err != nil {
+		return err
 	}
 
 	// On the host chain the capability may only be claimed during the OnChanOpenTry
@@ -90,12 +89,15 @@ func (k Keeper) OnChanOpenTry(
 		return err
 	}
 
-	// Register interchain account if it does not already exist
-	accAddr := strings.TrimPrefix(version, fmt.Sprintf("%s-", types.Version))
-	if err := k.RegisterInterchainAccount(ctx, accAddr, counterparty.PortId); err != nil {
-		return err
+	accAddr := types.GenerateAddress(counterparty.PortId)
+	parsedAddr := types.ParseAddressFromVersion(version)
+	if strings.Compare(parsedAddr, accAddr.String()) != 0 {
+		return sdkerrors.Wrapf(types.ErrInvalidAccountAddress, "invalid account address: %s, expected %s", parsedAddr, accAddr)
 	}
 
+	// Register interchain account if it does not already exist
+	k.RegisterInterchainAccount(ctx, accAddr, counterparty.PortId)
+
 	return nil
 }
 
@@ -109,13 +111,13 @@ func (k Keeper) OnChanOpenAck(
 	channelID string,
 	counterpartyVersion string,
 ) error {
-	if !strings.Contains(counterpartyVersion, types.Version) {
-		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: %s, expected %s", counterpartyVersion, types.Version)
+	if err := types.ValidateVersion(counterpartyVersion); err != nil {
+		return err
 	}
 
 	k.SetActiveChannel(ctx, portID, channelID)
 
-	accAddr := strings.TrimPrefix(counterpartyVersion, fmt.Sprintf("%s-", types.Version))
+	accAddr := types.ParseAddressFromVersion(counterpartyVersion)
 	k.SetInterchainAccountAddress(ctx, portID, accAddr)
 
 	return nil
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake_test.go b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
index 4ab8a2ee27d..328423088b0 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
@@ -1,8 +1,6 @@
 package keeper_test
 
 import (
-	"fmt"
-
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
 
 	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
@@ -64,7 +62,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenInit() {
 			suite.coordinator.SetupConnections(path)
 
 			// mock init interchain account
-			portID, err := types.GeneratePortID("owner", path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
+			portID, err := types.GeneratePortID(TestOwnerAddress, path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
 			suite.Require().NoError(err)
 			portCap := suite.chainA.GetSimApp().IBCKeeper.PortKeeper.BindPort(suite.chainA.GetContext(), portID)
 			suite.chainA.GetSimApp().ICAKeeper.ClaimCapability(suite.chainA.GetContext(), portCap, host.PortPath(portID))
@@ -138,6 +136,11 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 				suite.Require().NoError(err)
 			}, false,
 		},
+		{
+			"invalid account address", func() {
+				channel.Counterparty.PortId = "invalid-port-id"
+			}, false,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -146,7 +149,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			owner := "owner"
+			owner := TestOwnerAddress
 			counterpartyVersion = types.Version
 			suite.coordinator.SetupConnections(path)
 
@@ -160,7 +163,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 				Ordering:       channeltypes.ORDERED,
 				Counterparty:   counterparty,
 				ConnectionHops: []string{path.EndpointB.ConnectionID},
-				Version:        fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing")),
+				Version:        TestVersion,
 			}
 
 			chanCap, err = suite.chainB.App.GetScopedIBCKeeper().NewCapability(suite.chainB.GetContext(), host.ChannelCapabilityPath(path.EndpointB.ChannelConfig.PortID, path.EndpointB.ChannelID))
@@ -213,11 +216,10 @@ func (suite *KeeperTestSuite) TestOnChanOpenAck() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			owner := "owner"
-			counterpartyVersion = types.Version
+			counterpartyVersion = TestVersion
 			suite.coordinator.SetupConnections(path)
 
-			err := InitInterchainAccount(path.EndpointA, owner)
+			err := InitInterchainAccount(path.EndpointA, TestOwnerAddress)
 			suite.Require().NoError(err)
 
 			err = path.EndpointB.ChanOpenTry()
@@ -266,10 +268,9 @@ func (suite *KeeperTestSuite) TestOnChanOpenConfirm() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			owner := "owner"
 			suite.coordinator.SetupConnections(path)
 
-			err := InitInterchainAccount(path.EndpointA, owner)
+			err := InitInterchainAccount(path.EndpointA, TestOwnerAddress)
 			suite.Require().NoError(err)
 
 			err = path.EndpointB.ChanOpenTry()
diff --git a/modules/apps/27-interchain-accounts/keeper/keeper_test.go b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
index a2440c75e18..c2104776db3 100644
--- a/modules/apps/27-interchain-accounts/keeper/keeper_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
@@ -12,6 +12,13 @@ import (
 	ibctesting "github.com/cosmos/ibc-go/testing"
 )
 
+var (
+	// TestOwnerAddress defines a reusable bech32 address for testing purposes
+	TestOwnerAddress = "cosmos17dtl0mjt3t77kpuhg2edqzjpszulwhgzuj9ljs"
+	// TestVersion defines a resuable interchainaccounts version string for testing purposes
+	TestVersion = fmt.Sprintf("%s|%s", types.Version, types.GenerateAddress("ics-27-0-0-"+TestOwnerAddress))
+)
+
 type KeeperTestSuite struct {
 	suite.Suite
 
@@ -37,7 +44,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
+	path.EndpointB.ChannelConfig.Version = TestVersion
 
 	return path
 }
@@ -105,7 +112,7 @@ func (suite *KeeperTestSuite) TestGetInterchainAccountAddress() {
 	path := NewICAPath(suite.chainA, suite.chainB)
 	suite.coordinator.SetupConnections(path)
 
-	err := SetupICAPath(path, "testing")
+	err := SetupICAPath(path, TestOwnerAddress)
 	suite.Require().NoError(err)
 
 	counterpartyPortID := path.EndpointA.ChannelConfig.PortID
diff --git a/modules/apps/27-interchain-accounts/keeper/relay_test.go b/modules/apps/27-interchain-accounts/keeper/relay_test.go
index 66c3b22d51a..ea836fb8c05 100644
--- a/modules/apps/27-interchain-accounts/keeper/relay_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/relay_test.go
@@ -74,7 +74,7 @@ func (suite *KeeperTestSuite) TestTrySendTx() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			owner := "owner"
+			owner := TestOwnerAddress
 			suite.coordinator.SetupConnections(path)
 
 			err := suite.SetupICAPath(path, owner)
diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index f6f075a7f03..a97d733701f 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -270,5 +270,5 @@ func (am AppModule) NegotiateAppVersion(
 
 	addr := types.GenerateAddress(counterparty.PortId)
 
-	return fmt.Sprintf("%s-%s", types.Version, addr), nil
+	return fmt.Sprint(types.Version, types.Delimiter, addr), nil
 }
diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
index 58bf50579fd..6662d414163 100644
--- a/modules/apps/27-interchain-accounts/module_test.go
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -2,7 +2,6 @@ package interchain_accounts_test
 
 import (
 	"fmt"
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/suite"
@@ -12,6 +11,13 @@ import (
 	ibctesting "github.com/cosmos/ibc-go/testing"
 )
 
+var (
+	// TestOwnerAddress defines a reusable bech32 address for testing purposes
+	TestOwnerAddress = "cosmos17dtl0mjt3t77kpuhg2edqzjpszulwhgzuj9ljs"
+	// TestVersion defines a resuable interchainaccounts version string for testing purposes
+	TestVersion = fmt.Sprintf("%s|%s", types.Version, types.GenerateAddress("ics-27-0-0-"+TestOwnerAddress))
+)
+
 type InterchainAccountsTestSuite struct {
 	suite.Suite
 
@@ -37,7 +43,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
+	path.EndpointB.ChannelConfig.Version = TestVersion
 
 	return path
 }
@@ -57,7 +63,7 @@ func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
 	cbs, ok := suite.chainA.GetSimApp().GetIBCKeeper().Router.GetRoute(module)
 	suite.Require().True(ok)
 
-	counterpartyPortID, err := types.GeneratePortID("testing", path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
+	counterpartyPortID, err := types.GeneratePortID(TestOwnerAddress, path.EndpointA.ConnectionID, path.EndpointB.ConnectionID)
 	suite.Require().NoError(err)
 
 	counterparty := &channeltypes.Counterparty{
@@ -67,6 +73,5 @@ func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
 
 	version, err := cbs.NegotiateAppVersion(suite.chainA.GetContext(), channeltypes.ORDERED, path.EndpointA.ConnectionID, types.PortID, *counterparty, types.Version)
 	suite.Require().NoError(err)
-	suite.Require().True(strings.Contains(version, types.Version))
-	suite.Require().True(strings.Contains(version, types.GenerateAddress(counterpartyPortID).String()))
+	suite.Require().NoError(types.ValidateVersion(version))
 }
diff --git a/modules/apps/27-interchain-accounts/types/account.go b/modules/apps/27-interchain-accounts/types/account.go
index d7847b2d3f8..62ae112d2b3 100644
--- a/modules/apps/27-interchain-accounts/types/account.go
+++ b/modules/apps/27-interchain-accounts/types/account.go
@@ -5,13 +5,12 @@ import (
 	"fmt"
 	"strings"
 
-	yaml "gopkg.in/yaml.v2"
-
 	crypto "github.com/cosmos/cosmos-sdk/crypto/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	"github.com/cosmos/cosmos-sdk/types/address"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	"github.com/tendermint/tendermint/crypto/tmhash"
+	yaml "gopkg.in/yaml.v2"
 
 	connectiontypes "github.com/cosmos/ibc-go/modules/core/03-connection/types"
 )
@@ -20,10 +19,14 @@ const (
 	ICAPrefix string = "ics-27"
 )
 
-// GenerateAddress returns an sdk.AccAddress using the provided port identifier and derived from the IBC interchainaccounts module account
+// GenerateAddress returns an sdk.AccAddress using the provided port identifier
 func GenerateAddress(portID string) sdk.AccAddress {
-	moduleAcc := address.Module(ModuleName, ModuleAccountKey)
-	return sdk.AccAddress(address.Derive(moduleAcc, []byte(portID)))
+	return sdk.AccAddress(tmhash.SumTruncated([]byte(portID)))
+}
+
+// ParseAddressFromVersion trims the interchainaccounts version prefix and returns the associated account address
+func ParseAddressFromVersion(version string) string {
+	return strings.TrimPrefix(version, fmt.Sprint(Version, Delimiter))
 }
 
 // GeneratePortID generates the portID for a specific owner
@@ -33,21 +36,21 @@ func GenerateAddress(portID string) sdk.AccAddress {
 // https://github.com/seantking/ibc/tree/sean/ics-27-updates/spec/app/ics-027-interchain-accounts#registering--controlling-flows
 // TODO: update link to spec
 func GeneratePortID(owner, connectionID, counterpartyConnectionID string) (string, error) {
-	ownerID := strings.TrimSpace(owner)
-	if ownerID == "" {
-		return "", sdkerrors.Wrap(ErrInvalidOwnerAddress, "owner address cannot be empty")
+	if strings.TrimSpace(owner) == "" {
+		return "", sdkerrors.Wrap(ErrInvalidAccountAddress, "owner address cannot be empty")
 	}
+
 	connectionSeq, err := connectiontypes.ParseConnectionSequence(connectionID)
 	if err != nil {
 		return "", sdkerrors.Wrap(err, "invalid connection identifier")
 	}
+
 	counterpartyConnectionSeq, err := connectiontypes.ParseConnectionSequence(counterpartyConnectionID)
 	if err != nil {
 		return "", sdkerrors.Wrap(err, "invalid counterparty connection identifier")
 	}
 
-	portID := fmt.Sprintf("%s-%d-%d-%s", ICAPrefix, connectionSeq, counterpartyConnectionSeq, ownerID)
-	return portID, nil
+	return fmt.Sprintf("%s-%d-%d-%s", ICAPrefix, connectionSeq, counterpartyConnectionSeq, owner), nil
 }
 
 type InterchainAccountI interface {
diff --git a/modules/apps/27-interchain-accounts/types/account_test.go b/modules/apps/27-interchain-accounts/types/account_test.go
index e72241fc1e0..8f3bbc1126b 100644
--- a/modules/apps/27-interchain-accounts/types/account_test.go
+++ b/modules/apps/27-interchain-accounts/types/account_test.go
@@ -4,10 +4,16 @@ import (
 	"fmt"
 	"testing"
 
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/suite"
+
 	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
-	channeltypes "github.com/cosmos/ibc-go/modules/core/04-channel/types"
 	ibctesting "github.com/cosmos/ibc-go/testing"
-	"github.com/stretchr/testify/suite"
+)
+
+var (
+	// TestOwnerAddress defines a reusable bech32 address for testing purposes
+	TestOwnerAddress = "cosmos17dtl0mjt3t77kpuhg2edqzjpszulwhgzuj9ljs"
 )
 
 type TypesTestSuite struct {
@@ -26,26 +32,22 @@ func (suite *TypesTestSuite) SetupTest() {
 	suite.chainB = suite.coordinator.GetChain(ibctesting.GetChainID(1))
 }
 
-func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
-	path := ibctesting.NewPath(chainA, chainB)
-	path.EndpointA.ChannelConfig.PortID = types.PortID
-	path.EndpointB.ChannelConfig.PortID = types.PortID
-	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
-	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
-	path.EndpointA.ChannelConfig.Version = types.Version
-	path.EndpointB.ChannelConfig.Version = fmt.Sprintf("%s-%s", types.Version, types.GenerateAddress("ics-27-0-0-testing"))
-
-	return path
-}
-
 func TestTypesTestSuite(t *testing.T) {
 	suite.Run(t, new(TypesTestSuite))
 }
 
+func (suite *TypesTestSuite) TestGenerateAddress() {
+	addr := types.GenerateAddress("test-port-id")
+	accAddr, err := sdk.AccAddressFromBech32(addr.String())
+
+	suite.Require().NoError(err, "TestGenerateAddress failed")
+	suite.Require().NotEmpty(accAddr)
+}
+
 func (suite *TypesTestSuite) TestGeneratePortID() {
 	var (
 		path  *ibctesting.Path
-		owner = "testing"
+		owner = TestOwnerAddress
 	)
 
 	testCases := []struct {
@@ -57,7 +59,7 @@ func (suite *TypesTestSuite) TestGeneratePortID() {
 		{
 			"success",
 			func() {},
-			"ics-27-0-0-testing",
+			fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress),
 			true,
 		},
 		{
@@ -65,7 +67,7 @@ func (suite *TypesTestSuite) TestGeneratePortID() {
 			func() {
 				path.EndpointA.ConnectionID = "connection-1"
 			},
-			"ics-27-1-0-testing",
+			fmt.Sprintf("ics-27-1-0-%s", TestOwnerAddress),
 			true,
 		},
 		{
@@ -98,7 +100,7 @@ func (suite *TypesTestSuite) TestGeneratePortID() {
 		tc := tc
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
-			path = NewICAPath(suite.chainA, suite.chainB)
+			path = ibctesting.NewPath(suite.chainA, suite.chainB)
 			suite.coordinator.Setup(path)
 
 			tc.malleate()
diff --git a/modules/apps/27-interchain-accounts/types/errors.go b/modules/apps/27-interchain-accounts/types/errors.go
index 32425a81071..5c5bf3fed44 100644
--- a/modules/apps/27-interchain-accounts/types/errors.go
+++ b/modules/apps/27-interchain-accounts/types/errors.go
@@ -11,9 +11,9 @@ var (
 	ErrUnsupportedChain            = sdkerrors.Register(ModuleName, 5, "unsupported chain")
 	ErrInvalidOutgoingData         = sdkerrors.Register(ModuleName, 6, "invalid outgoing data")
 	ErrInvalidRoute                = sdkerrors.Register(ModuleName, 7, "invalid route")
-	ErrInterchainAccountNotFound   = sdkerrors.Register(ModuleName, 8, "Interchain Account not found")
-	ErrInterchainAccountAlreadySet = sdkerrors.Register(ModuleName, 9, "Interchain Account is already set")
+	ErrInterchainAccountNotFound   = sdkerrors.Register(ModuleName, 8, "interchain account not found")
+	ErrInterchainAccountAlreadySet = sdkerrors.Register(ModuleName, 9, "interchain account is already set")
 	ErrActiveChannelNotFound       = sdkerrors.Register(ModuleName, 10, "no active channel for this owner")
 	ErrInvalidVersion              = sdkerrors.Register(ModuleName, 11, "invalid interchain accounts version")
-	ErrInvalidOwnerAddress         = sdkerrors.Register(ModuleName, 12, "invalid owner address")
+	ErrInvalidAccountAddress       = sdkerrors.Register(ModuleName, 12, "invalid account address")
 )
diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index 3c1a721d9da..d5b7fdf4a38 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -1,6 +1,8 @@
 package types
 
-import "fmt"
+import (
+	"fmt"
+)
 
 const (
 	// ModuleName defines the Interchain Account module name
@@ -21,13 +23,13 @@ const (
 
 	// QuerierRoute is the querier route for IBC interchainaccounts
 	QuerierRoute = ModuleName
+
+	// Delimiter is the delimiter used when parsing the interchainaccounts version string
+	Delimiter = "|"
 )
 
 var (
-	// ModuleAccountKey defines the key used to construct to the IBC interchainaccounts module account address
-	ModuleAccountKey = []byte(ModuleName)
-
-	// Key to store portID in our store
+	// PortKey defines the key to store the port ID in store
 	PortKey = "portID"
 )
 
diff --git a/modules/apps/27-interchain-accounts/types/validate.go b/modules/apps/27-interchain-accounts/types/validate.go
new file mode 100644
index 00000000000..fbbf2152fd0
--- /dev/null
+++ b/modules/apps/27-interchain-accounts/types/validate.go
@@ -0,0 +1,40 @@
+package types
+
+import (
+	"regexp"
+	"strings"
+
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// DefaultMaxAddrLength defines the default maximum character length used in validation of addresses
+var DefaultMaxAddrLength = 64
+
+// DefaultMinAddrLength defines the default minimum character length used in validation of addresses
+var DefaultMinAddrLength = 32
+
+// IsValidAddr defines a regular expression to check if the provided string consists of
+// strictly alphanumeric characters
+var IsValidAddr = regexp.MustCompile("^[a-zA-Z0-9]*$").MatchString
+
+// ValidateVersion performs basic validation of the provided interchainaccounts version string
+func ValidateVersion(version string) error {
+	s := strings.Split(version, Delimiter)
+
+	if s[0] != Version {
+		return sdkerrors.Wrapf(ErrInvalidVersion, "invalid version: expected %s, got %s", Version, s[0])
+	}
+
+	if len(s) > 1 {
+		if !IsValidAddr(s[1]) && len(s[1]) <= DefaultMaxAddrLength && len(s[1]) >= DefaultMinAddrLength {
+			return sdkerrors.Wrapf(
+				ErrInvalidAccountAddress,
+				"address must contain strictly alphanumeric characters, %d-%d characters in length",
+				DefaultMinAddrLength,
+				DefaultMaxAddrLength,
+			)
+		}
+	}
+
+	return nil
+}

From 4ee74bfd8a6ab4837a0f89580a4ad8a991444c25 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Thu, 16 Sep 2021 15:36:23 +0200
Subject: [PATCH 08/17] removing redundant local var - owner

---
 modules/apps/27-interchain-accounts/keeper/handshake_test.go | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/keeper/handshake_test.go b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
index 328423088b0..214314f9bb4 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
@@ -149,11 +149,10 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			owner := TestOwnerAddress
 			counterpartyVersion = types.Version
 			suite.coordinator.SetupConnections(path)
 
-			err := InitInterchainAccount(path.EndpointA, owner)
+			err := InitInterchainAccount(path.EndpointA, TestOwnerAddress)
 			suite.Require().NoError(err)
 
 			// default values

From b2f3e3b29223cbdb6870405c4c47afd191731d2d Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Thu, 16 Sep 2021 15:40:55 +0200
Subject: [PATCH 09/17] updating Delimiter godoc

---
 modules/apps/27-interchain-accounts/types/keys.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index d5b7fdf4a38..c4c1c786d76 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -24,7 +24,7 @@ const (
 	// QuerierRoute is the querier route for IBC interchainaccounts
 	QuerierRoute = ModuleName
 
-	// Delimiter is the delimiter used when parsing the interchainaccounts version string
+	// Delimiter is the delimiter used for the interchainaccounts version string
 	Delimiter = "|"
 )
 

From c7d78041f11e99e3fe401e5d9b01e1b4bf013809 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Thu, 16 Sep 2021 18:21:49 +0200
Subject: [PATCH 10/17] updating validation logic

---
 modules/apps/27-interchain-accounts/module.go         | 4 +---
 modules/apps/27-interchain-accounts/types/validate.go | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index a97d733701f..bcb4e9c17ba 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -268,7 +268,5 @@ func (am AppModule) NegotiateAppVersion(
 		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.Version, proposedVersion)
 	}
 
-	addr := types.GenerateAddress(counterparty.PortId)
-
-	return fmt.Sprint(types.Version, types.Delimiter, addr), nil
+	return fmt.Sprint(types.Version, types.Delimiter, types.GenerateAddress(counterparty.PortId)), nil
 }
diff --git a/modules/apps/27-interchain-accounts/types/validate.go b/modules/apps/27-interchain-accounts/types/validate.go
index fbbf2152fd0..1c305bd3899 100644
--- a/modules/apps/27-interchain-accounts/types/validate.go
+++ b/modules/apps/27-interchain-accounts/types/validate.go
@@ -26,7 +26,7 @@ func ValidateVersion(version string) error {
 	}
 
 	if len(s) > 1 {
-		if !IsValidAddr(s[1]) && len(s[1]) <= DefaultMaxAddrLength && len(s[1]) >= DefaultMinAddrLength {
+		if !IsValidAddr(s[1]) || len(s[1]) > DefaultMaxAddrLength || len(s[1]) < DefaultMinAddrLength {
 			return sdkerrors.Wrapf(
 				ErrInvalidAccountAddress,
 				"address must contain strictly alphanumeric characters, %d-%d characters in length",

From 001313ce2864605fcf7a737958b7dddfd5b023ed Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Thu, 16 Sep 2021 18:37:15 +0200
Subject: [PATCH 11/17] adding test cases for ValidateVersion

---
 .../types/validate_test.go                    | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 modules/apps/27-interchain-accounts/types/validate_test.go

diff --git a/modules/apps/27-interchain-accounts/types/validate_test.go b/modules/apps/27-interchain-accounts/types/validate_test.go
new file mode 100644
index 00000000000..656e629954f
--- /dev/null
+++ b/modules/apps/27-interchain-accounts/types/validate_test.go
@@ -0,0 +1,53 @@
+package types_test
+
+import (
+	"fmt"
+
+	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
+)
+
+func (suite *TypesTestSuite) TestValidateVersion() {
+	testCases := []struct {
+		name    string
+		version string
+		expPass bool
+	}{
+		{
+			"success",
+			fmt.Sprint(types.Version, types.Delimiter, TestOwnerAddress),
+			true,
+		},
+		{
+			"invalid version",
+			"ics27-5|abc123",
+			false,
+		},
+		{
+			"invalid account address - 31 chars",
+			"ics27-1|xtignpvthxbwxtmnzyfwhhywobaatlt",
+			false,
+		},
+		{
+			"invalid account address - 65 chars",
+			"ics27-1|ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt",
+			false,
+		},
+		{
+			"invalid account address - non alphanumeric characters",
+			"ics27-1|abc_123",
+			false,
+		},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(tc.name, func() {
+			err := types.ValidateVersion(tc.version)
+
+			if tc.expPass {
+				suite.Require().NoError(err, tc.name)
+			} else {
+				suite.Require().Error(err, tc.name)
+			}
+		})
+	}
+}

From d6725e1794b81182e5ea3d398d1742bbc04c2426 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Fri, 17 Sep 2021 10:00:56 +0200
Subject: [PATCH 12/17] adding additional validation testcase, updating godocs

---
 .../apps/27-interchain-accounts/types/validate.go   |  3 ++-
 .../27-interchain-accounts/types/validate_test.go   | 13 +++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/types/validate.go b/modules/apps/27-interchain-accounts/types/validate.go
index 1c305bd3899..9e1bac5851b 100644
--- a/modules/apps/27-interchain-accounts/types/validate.go
+++ b/modules/apps/27-interchain-accounts/types/validate.go
@@ -17,7 +17,8 @@ var DefaultMinAddrLength = 32
 // strictly alphanumeric characters
 var IsValidAddr = regexp.MustCompile("^[a-zA-Z0-9]*$").MatchString
 
-// ValidateVersion performs basic validation of the provided interchainaccounts version string
+// ValidateVersion performs basic validation of the provided ics27 version string
+// When no delimiter is present it compares against the expected version
 func ValidateVersion(version string) error {
 	s := strings.Split(version, Delimiter)
 
diff --git a/modules/apps/27-interchain-accounts/types/validate_test.go b/modules/apps/27-interchain-accounts/types/validate_test.go
index 656e629954f..d85e7e2f271 100644
--- a/modules/apps/27-interchain-accounts/types/validate_test.go
+++ b/modules/apps/27-interchain-accounts/types/validate_test.go
@@ -17,24 +17,29 @@ func (suite *TypesTestSuite) TestValidateVersion() {
 			fmt.Sprint(types.Version, types.Delimiter, TestOwnerAddress),
 			true,
 		},
+		{
+			"success - version only",
+			fmt.Sprint(types.Version),
+			true,
+		},
 		{
 			"invalid version",
-			"ics27-5|abc123",
+			fmt.Sprint("ics27-5", types.Delimiter, TestOwnerAddress),
 			false,
 		},
 		{
 			"invalid account address - 31 chars",
-			"ics27-1|xtignpvthxbwxtmnzyfwhhywobaatlt",
+			fmt.Sprint(types.Version, types.Delimiter, "xtignpvthxbwxtmnzyfwhhywobaatlt"),
 			false,
 		},
 		{
 			"invalid account address - 65 chars",
-			"ics27-1|ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt",
+			fmt.Sprint(types.Version, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
 			false,
 		},
 		{
 			"invalid account address - non alphanumeric characters",
-			"ics27-1|abc_123",
+			fmt.Sprint(types.Version, types.Delimiter, "-_-"),
 			false,
 		},
 	}

From 32240ffa9e804683b8dbfefbdda7aaf30ca620c9 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Fri, 17 Sep 2021 16:26:12 +0200
Subject: [PATCH 13/17] updating Version -> VersionPrefix, error msgs,
 validation tests

---
 .../27-interchain-accounts/keeper/account.go  |  2 +-
 .../keeper/handshake.go                       |  6 ++--
 .../keeper/handshake_test.go                  |  4 +--
 .../keeper/keeper_test.go                     |  6 ++--
 modules/apps/27-interchain-accounts/module.go |  6 ++--
 .../27-interchain-accounts/module_test.go     |  9 ++++--
 .../27-interchain-accounts/types/account.go   |  2 +-
 .../apps/27-interchain-accounts/types/keys.go | 30 ++++++++++---------
 .../27-interchain-accounts/types/validate.go  | 18 +++++------
 .../types/validate_test.go                    | 19 +++++++-----
 10 files changed, 56 insertions(+), 46 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/keeper/account.go b/modules/apps/27-interchain-accounts/keeper/account.go
index 5f31c3df0c8..814e96d6dad 100644
--- a/modules/apps/27-interchain-accounts/keeper/account.go
+++ b/modules/apps/27-interchain-accounts/keeper/account.go
@@ -31,7 +31,7 @@ func (k Keeper) InitInterchainAccount(ctx sdk.Context, connectionID, counterpart
 		return sdkerrors.Wrap(err, "unable to bind to newly generated portID")
 	}
 
-	msg := channeltypes.NewMsgChannelOpenInit(portID, types.Version, channeltypes.ORDERED, []string{connectionID}, types.PortID, types.ModuleName)
+	msg := channeltypes.NewMsgChannelOpenInit(portID, types.VersionPrefix, channeltypes.ORDERED, []string{connectionID}, types.PortID, types.ModuleName)
 	handler := k.msgRouter.Handler(msg)
 	if _, err := handler(ctx, msg); err != nil {
 		return err
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake.go b/modules/apps/27-interchain-accounts/keeper/handshake.go
index e6d0b32ca8d..19dd325ba66 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake.go
@@ -1,8 +1,6 @@
 package keeper
 
 import (
-	"strings"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
@@ -91,8 +89,8 @@ func (k Keeper) OnChanOpenTry(
 
 	accAddr := types.GenerateAddress(counterparty.PortId)
 	parsedAddr := types.ParseAddressFromVersion(version)
-	if strings.Compare(parsedAddr, accAddr.String()) != 0 {
-		return sdkerrors.Wrapf(types.ErrInvalidAccountAddress, "invalid account address: %s, expected %s", parsedAddr, accAddr)
+	if parsedAddr != accAddr.String() {
+		return sdkerrors.Wrapf(types.ErrInvalidAccountAddress, "version contains invalid account address: expected %s, got %s", parsedAddr, accAddr)
 	}
 
 	// Register interchain account if it does not already exist
diff --git a/modules/apps/27-interchain-accounts/keeper/handshake_test.go b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
index 214314f9bb4..d3ba9b20a31 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake_test.go
@@ -75,7 +75,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenInit() {
 				Ordering:       channeltypes.ORDERED,
 				Counterparty:   counterparty,
 				ConnectionHops: []string{path.EndpointA.ConnectionID},
-				Version:        types.Version,
+				Version:        types.VersionPrefix,
 			}
 
 			chanCap, err = suite.chainA.App.GetScopedIBCKeeper().NewCapability(suite.chainA.GetContext(), host.ChannelCapabilityPath(portID, path.EndpointA.ChannelID))
@@ -149,7 +149,7 @@ func (suite *KeeperTestSuite) TestOnChanOpenTry() {
 		suite.Run(tc.name, func() {
 			suite.SetupTest() // reset
 			path = NewICAPath(suite.chainA, suite.chainB)
-			counterpartyVersion = types.Version
+			counterpartyVersion = types.VersionPrefix
 			suite.coordinator.SetupConnections(path)
 
 			err := InitInterchainAccount(path.EndpointA, TestOwnerAddress)
diff --git a/modules/apps/27-interchain-accounts/keeper/keeper_test.go b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
index c2104776db3..d95f1fc6a57 100644
--- a/modules/apps/27-interchain-accounts/keeper/keeper_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
@@ -15,8 +15,10 @@ import (
 var (
 	// TestOwnerAddress defines a reusable bech32 address for testing purposes
 	TestOwnerAddress = "cosmos17dtl0mjt3t77kpuhg2edqzjpszulwhgzuj9ljs"
+	// TestPortID defines a resuable port identifier for testing purposes
+	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = fmt.Sprintf("%s|%s", types.Version, types.GenerateAddress("ics-27-0-0-"+TestOwnerAddress))
+	TestVersion = fmt.Sprintf("%s|%s", types.VersionPrefix, types.GenerateAddress(TestPortID))
 )
 
 type KeeperTestSuite struct {
@@ -43,7 +45,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointB.ChannelConfig.PortID = types.PortID
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
-	path.EndpointA.ChannelConfig.Version = types.Version
+	path.EndpointA.ChannelConfig.Version = types.VersionPrefix
 	path.EndpointB.ChannelConfig.Version = TestVersion
 
 	return path
diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index bcb4e9c17ba..db077fa1d96 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -264,9 +264,9 @@ func (am AppModule) NegotiateAppVersion(
 	counterparty channeltypes.Counterparty,
 	proposedVersion string,
 ) (string, error) {
-	if proposedVersion != types.Version {
-		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.Version, proposedVersion)
+	if proposedVersion != types.VersionPrefix {
+		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.VersionPrefix, proposedVersion)
 	}
 
-	return fmt.Sprint(types.Version, types.Delimiter, types.GenerateAddress(counterparty.PortId)), nil
+	return types.NewAppVersion(types.GenerateAddress(counterparty.PortId).String()), nil
 }
diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
index 6662d414163..e4c7b077456 100644
--- a/modules/apps/27-interchain-accounts/module_test.go
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -14,8 +14,10 @@ import (
 var (
 	// TestOwnerAddress defines a reusable bech32 address for testing purposes
 	TestOwnerAddress = "cosmos17dtl0mjt3t77kpuhg2edqzjpszulwhgzuj9ljs"
+	// TestPortID defines a resuable port identifier for testing purposes
+	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = fmt.Sprintf("%s|%s", types.Version, types.GenerateAddress("ics-27-0-0-"+TestOwnerAddress))
+	TestVersion = fmt.Sprintf("%s|%s", types.VersionPrefix, types.GenerateAddress(TestPortID))
 )
 
 type InterchainAccountsTestSuite struct {
@@ -42,7 +44,7 @@ func NewICAPath(chainA, chainB *ibctesting.TestChain) *ibctesting.Path {
 	path.EndpointB.ChannelConfig.PortID = types.PortID
 	path.EndpointA.ChannelConfig.Order = channeltypes.ORDERED
 	path.EndpointB.ChannelConfig.Order = channeltypes.ORDERED
-	path.EndpointA.ChannelConfig.Version = types.Version
+	path.EndpointA.ChannelConfig.Version = types.VersionPrefix
 	path.EndpointB.ChannelConfig.Version = TestVersion
 
 	return path
@@ -71,7 +73,8 @@ func (suite *InterchainAccountsTestSuite) TestNegotiateAppVersion() {
 		ChannelId: path.EndpointB.ChannelID,
 	}
 
-	version, err := cbs.NegotiateAppVersion(suite.chainA.GetContext(), channeltypes.ORDERED, path.EndpointA.ConnectionID, types.PortID, *counterparty, types.Version)
+	version, err := cbs.NegotiateAppVersion(suite.chainA.GetContext(), channeltypes.ORDERED, path.EndpointA.ConnectionID, types.PortID, *counterparty, types.VersionPrefix)
 	suite.Require().NoError(err)
 	suite.Require().NoError(types.ValidateVersion(version))
+	suite.Require().Equal(TestVersion, version)
 }
diff --git a/modules/apps/27-interchain-accounts/types/account.go b/modules/apps/27-interchain-accounts/types/account.go
index 62ae112d2b3..7948e2e6afa 100644
--- a/modules/apps/27-interchain-accounts/types/account.go
+++ b/modules/apps/27-interchain-accounts/types/account.go
@@ -26,7 +26,7 @@ func GenerateAddress(portID string) sdk.AccAddress {
 
 // ParseAddressFromVersion trims the interchainaccounts version prefix and returns the associated account address
 func ParseAddressFromVersion(version string) string {
-	return strings.TrimPrefix(version, fmt.Sprint(Version, Delimiter))
+	return strings.TrimPrefix(version, fmt.Sprint(VersionPrefix, Delimiter))
 }
 
 // GeneratePortID generates the portID for a specific owner
diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index c4c1c786d76..011c5e68ec4 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -5,42 +5,44 @@ import (
 )
 
 const (
-	// ModuleName defines the Interchain Account module name
+	// ModuleName defines the interchain accounts module name
 	ModuleName = "interchainaccounts"
 
-	// Version defines the current version the IBC interchainaccounts
-	// module supports
-	Version = "ics27-1"
+	// VersionPrefix defines the current version for interchain accounts
+	VersionPrefix = "ics27-1"
 
-	// PortID is the default port id that the interchainaccounts module binds to
+	// PortID is the default port id that the interchain accounts module binds to
 	PortID = "ibcaccount"
 
-	// StoreKey is the store key string for IBC interchainaccounts
+	// StoreKey is the store key string for interchain accounts
 	StoreKey = ModuleName
 
-	// RouterKey is the message route for IBC interchainaccounts
+	// RouterKey is the message route for interchain accounts
 	RouterKey = ModuleName
 
-	// QuerierRoute is the querier route for IBC interchainaccounts
+	// QuerierRoute is the querier route for interchain accounts
 	QuerierRoute = ModuleName
 
-	// Delimiter is the delimiter used for the interchainaccounts version string
+	// Delimiter is the delimiter used for the interchain accounts version string
 	Delimiter = "|"
 )
 
 var (
 	// PortKey defines the key to store the port ID in store
-	PortKey = "portID"
+	PortKey = []byte{0x01}
 )
 
+// NewVersion returns a complete version string in the format: VersionPrefix + Delimter + AccAddress
+func NewAppVersion(addr string) string {
+	return fmt.Sprint(VersionPrefix, Delimiter, addr)
+}
+
+// KeyActiveChannel creates and returns a new key used for active channels store operations
 func KeyActiveChannel(portId string) []byte {
 	return []byte(fmt.Sprintf("activeChannel/%s", portId))
 }
 
+// KeyOwnerAccount creates and returns a new key used for owner account store operations
 func KeyOwnerAccount(portId string) []byte {
 	return []byte(fmt.Sprintf("owner/%s", portId))
 }
-
-func GetIdentifier(portID, channelID string) string {
-	return fmt.Sprintf("%s/%s/", portID, channelID)
-}
diff --git a/modules/apps/27-interchain-accounts/types/validate.go b/modules/apps/27-interchain-accounts/types/validate.go
index 9e1bac5851b..596d0c467ae 100644
--- a/modules/apps/27-interchain-accounts/types/validate.go
+++ b/modules/apps/27-interchain-accounts/types/validate.go
@@ -8,10 +8,7 @@ import (
 )
 
 // DefaultMaxAddrLength defines the default maximum character length used in validation of addresses
-var DefaultMaxAddrLength = 64
-
-// DefaultMinAddrLength defines the default minimum character length used in validation of addresses
-var DefaultMinAddrLength = 32
+var DefaultMaxAddrLength = 128
 
 // IsValidAddr defines a regular expression to check if the provided string consists of
 // strictly alphanumeric characters
@@ -22,16 +19,19 @@ var IsValidAddr = regexp.MustCompile("^[a-zA-Z0-9]*$").MatchString
 func ValidateVersion(version string) error {
 	s := strings.Split(version, Delimiter)
 
-	if s[0] != Version {
-		return sdkerrors.Wrapf(ErrInvalidVersion, "invalid version: expected %s, got %s", Version, s[0])
+	if s[0] != VersionPrefix {
+		return sdkerrors.Wrapf(ErrInvalidVersion, "expected %s, got %s", VersionPrefix, s[0])
 	}
 
 	if len(s) > 1 {
-		if !IsValidAddr(s[1]) || len(s[1]) > DefaultMaxAddrLength || len(s[1]) < DefaultMinAddrLength {
+		if len(s) != 2 {
+			return sdkerrors.Wrap(ErrInvalidAccountAddress, "unexpected address format")
+		}
+
+		if !IsValidAddr(s[1]) || len(s[1]) == 0 || len(s[1]) > DefaultMaxAddrLength {
 			return sdkerrors.Wrapf(
 				ErrInvalidAccountAddress,
-				"address must contain strictly alphanumeric characters, %d-%d characters in length",
-				DefaultMinAddrLength,
+				"address must contain strictly alphanumeric characters, not exceeding %d characters in length",
 				DefaultMaxAddrLength,
 			)
 		}
diff --git a/modules/apps/27-interchain-accounts/types/validate_test.go b/modules/apps/27-interchain-accounts/types/validate_test.go
index d85e7e2f271..beaaf9443a6 100644
--- a/modules/apps/27-interchain-accounts/types/validate_test.go
+++ b/modules/apps/27-interchain-accounts/types/validate_test.go
@@ -14,12 +14,12 @@ func (suite *TypesTestSuite) TestValidateVersion() {
 	}{
 		{
 			"success",
-			fmt.Sprint(types.Version, types.Delimiter, TestOwnerAddress),
+			fmt.Sprint(types.VersionPrefix, types.Delimiter, TestOwnerAddress),
 			true,
 		},
 		{
 			"success - version only",
-			fmt.Sprint(types.Version),
+			fmt.Sprint(types.VersionPrefix),
 			true,
 		},
 		{
@@ -28,18 +28,23 @@ func (suite *TypesTestSuite) TestValidateVersion() {
 			false,
 		},
 		{
-			"invalid account address - 31 chars",
-			fmt.Sprint(types.Version, types.Delimiter, "xtignpvthxbwxtmnzyfwhhywobaatlt"),
+			"invalid account address - empty",
+			fmt.Sprint(types.VersionPrefix, types.Delimiter, ""),
 			false,
 		},
 		{
-			"invalid account address - 65 chars",
-			fmt.Sprint(types.Version, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
+			"invalid account address - exceeded character length",
+			fmt.Sprint(types.VersionPrefix, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatltfwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
 			false,
 		},
 		{
 			"invalid account address - non alphanumeric characters",
-			fmt.Sprint(types.Version, types.Delimiter, "-_-"),
+			fmt.Sprint(types.VersionPrefix, types.Delimiter, "-_-"),
+			false,
+		},
+		{
+			"invalid account address - address contains additional delimiter",
+			fmt.Sprint(types.VersionPrefix, types.Delimiter, "cosmos17dtl0mjt3t77kpu|hg2edqzjpszulwhgzuj9ljs"),
 			false,
 		},
 	}

From e4af997e223b7353a9708fa65683cb0c1aad3f89 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Fri, 17 Sep 2021 16:51:44 +0200
Subject: [PATCH 14/17] updating NewAppVersion func sig and usage

---
 .../27-interchain-accounts/keeper/keeper_test.go |  2 +-
 modules/apps/27-interchain-accounts/module.go    |  2 +-
 .../apps/27-interchain-accounts/module_test.go   |  2 +-
 .../apps/27-interchain-accounts/types/keys.go    |  4 ++--
 .../types/validate_test.go                       | 16 +++++++---------
 5 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/keeper/keeper_test.go b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
index d95f1fc6a57..b7aa9093388 100644
--- a/modules/apps/27-interchain-accounts/keeper/keeper_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
@@ -18,7 +18,7 @@ var (
 	// TestPortID defines a resuable port identifier for testing purposes
 	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = fmt.Sprintf("%s|%s", types.VersionPrefix, types.GenerateAddress(TestPortID))
+	TestVersion = types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(TestPortID).String())
 )
 
 type KeeperTestSuite struct {
diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index db077fa1d96..3b9f8076f4a 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -268,5 +268,5 @@ func (am AppModule) NegotiateAppVersion(
 		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.VersionPrefix, proposedVersion)
 	}
 
-	return types.NewAppVersion(types.GenerateAddress(counterparty.PortId).String()), nil
+	return types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(counterparty.PortId).String()), nil
 }
diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
index e4c7b077456..87fe9353b31 100644
--- a/modules/apps/27-interchain-accounts/module_test.go
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -17,7 +17,7 @@ var (
 	// TestPortID defines a resuable port identifier for testing purposes
 	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = fmt.Sprintf("%s|%s", types.VersionPrefix, types.GenerateAddress(TestPortID))
+	TestVersion = types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(TestPortID).String())
 )
 
 type InterchainAccountsTestSuite struct {
diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index 011c5e68ec4..47df826dece 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -33,8 +33,8 @@ var (
 )
 
 // NewVersion returns a complete version string in the format: VersionPrefix + Delimter + AccAddress
-func NewAppVersion(addr string) string {
-	return fmt.Sprint(VersionPrefix, Delimiter, addr)
+func NewAppVersion(versionPrefix, delimiter, addr string) string {
+	return fmt.Sprint(versionPrefix, delimiter, addr)
 }
 
 // KeyActiveChannel creates and returns a new key used for active channels store operations
diff --git a/modules/apps/27-interchain-accounts/types/validate_test.go b/modules/apps/27-interchain-accounts/types/validate_test.go
index beaaf9443a6..3f7157ca696 100644
--- a/modules/apps/27-interchain-accounts/types/validate_test.go
+++ b/modules/apps/27-interchain-accounts/types/validate_test.go
@@ -1,8 +1,6 @@
 package types_test
 
 import (
-	"fmt"
-
 	"github.com/cosmos/ibc-go/modules/apps/27-interchain-accounts/types"
 )
 
@@ -14,37 +12,37 @@ func (suite *TypesTestSuite) TestValidateVersion() {
 	}{
 		{
 			"success",
-			fmt.Sprint(types.VersionPrefix, types.Delimiter, TestOwnerAddress),
+			types.NewAppVersion(types.VersionPrefix, types.Delimiter, TestOwnerAddress),
 			true,
 		},
 		{
 			"success - version only",
-			fmt.Sprint(types.VersionPrefix),
+			types.NewAppVersion(types.VersionPrefix, "", ""),
 			true,
 		},
 		{
 			"invalid version",
-			fmt.Sprint("ics27-5", types.Delimiter, TestOwnerAddress),
+			types.NewAppVersion("ics27-5", types.Delimiter, TestOwnerAddress),
 			false,
 		},
 		{
 			"invalid account address - empty",
-			fmt.Sprint(types.VersionPrefix, types.Delimiter, ""),
+			types.NewAppVersion(types.VersionPrefix, types.Delimiter, ""),
 			false,
 		},
 		{
 			"invalid account address - exceeded character length",
-			fmt.Sprint(types.VersionPrefix, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatltfwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
+			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatltfwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
 			false,
 		},
 		{
 			"invalid account address - non alphanumeric characters",
-			fmt.Sprint(types.VersionPrefix, types.Delimiter, "-_-"),
+			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "-_-"),
 			false,
 		},
 		{
 			"invalid account address - address contains additional delimiter",
-			fmt.Sprint(types.VersionPrefix, types.Delimiter, "cosmos17dtl0mjt3t77kpu|hg2edqzjpszulwhgzuj9ljs"),
+			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "cosmos17dtl0mjt3t77kpu|hg2edqzjpszulwhgzuj9ljs"),
 			false,
 		},
 	}

From 18e9601ff8c8eb8a526609cedb724cf60b207d85 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Mon, 20 Sep 2021 13:25:24 +0200
Subject: [PATCH 15/17] updating NewAppVersion args and returning more
 appropriate errors for handshake

---
 .../27-interchain-accounts/keeper/handshake.go   |  8 ++++----
 .../27-interchain-accounts/keeper/keeper_test.go |  2 +-
 modules/apps/27-interchain-accounts/module.go    |  2 +-
 .../apps/27-interchain-accounts/module_test.go   |  2 +-
 .../apps/27-interchain-accounts/types/keys.go    |  4 ++--
 .../types/validate_test.go                       | 16 ++++++++--------
 6 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/keeper/handshake.go b/modules/apps/27-interchain-accounts/keeper/handshake.go
index 19dd325ba66..d3ea5de071a 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake.go
@@ -38,7 +38,7 @@ func (k Keeper) OnChanOpenInit(
 	}
 
 	if err := types.ValidateVersion(version); err != nil {
-		return err
+		return sdkerrors.Wrap(err, "version validation failed")
 	}
 
 	existingChannelID, found := k.GetActiveChannel(ctx, portID)
@@ -74,11 +74,11 @@ func (k Keeper) OnChanOpenTry(
 	}
 
 	if err := types.ValidateVersion(version); err != nil {
-		return err
+		return sdkerrors.Wrap(err, "version validation failed")
 	}
 
 	if err := types.ValidateVersion(counterpartyVersion); err != nil {
-		return err
+		return sdkerrors.Wrap(err, "counterparty version validation failed")
 	}
 
 	// On the host chain the capability may only be claimed during the OnChanOpenTry
@@ -110,7 +110,7 @@ func (k Keeper) OnChanOpenAck(
 	counterpartyVersion string,
 ) error {
 	if err := types.ValidateVersion(counterpartyVersion); err != nil {
-		return err
+		return sdkerrors.Wrap(err, "counterparty version validation failed")
 	}
 
 	k.SetActiveChannel(ctx, portID, channelID)
diff --git a/modules/apps/27-interchain-accounts/keeper/keeper_test.go b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
index b7aa9093388..0f7c12d8189 100644
--- a/modules/apps/27-interchain-accounts/keeper/keeper_test.go
+++ b/modules/apps/27-interchain-accounts/keeper/keeper_test.go
@@ -18,7 +18,7 @@ var (
 	// TestPortID defines a resuable port identifier for testing purposes
 	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(TestPortID).String())
+	TestVersion = types.NewAppVersion(types.VersionPrefix, types.GenerateAddress(TestPortID).String())
 )
 
 type KeeperTestSuite struct {
diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index 3b9f8076f4a..efa808f8d01 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -268,5 +268,5 @@ func (am AppModule) NegotiateAppVersion(
 		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "failed to negotiate app version: expected %s, got %s", types.VersionPrefix, proposedVersion)
 	}
 
-	return types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(counterparty.PortId).String()), nil
+	return types.NewAppVersion(types.VersionPrefix, types.GenerateAddress(counterparty.PortId).String()), nil
 }
diff --git a/modules/apps/27-interchain-accounts/module_test.go b/modules/apps/27-interchain-accounts/module_test.go
index 87fe9353b31..fbfea84a189 100644
--- a/modules/apps/27-interchain-accounts/module_test.go
+++ b/modules/apps/27-interchain-accounts/module_test.go
@@ -17,7 +17,7 @@ var (
 	// TestPortID defines a resuable port identifier for testing purposes
 	TestPortID = fmt.Sprintf("ics-27-0-0-%s", TestOwnerAddress)
 	// TestVersion defines a resuable interchainaccounts version string for testing purposes
-	TestVersion = types.NewAppVersion(types.VersionPrefix, types.Delimiter, types.GenerateAddress(TestPortID).String())
+	TestVersion = types.NewAppVersion(types.VersionPrefix, types.GenerateAddress(TestPortID).String())
 )
 
 type InterchainAccountsTestSuite struct {
diff --git a/modules/apps/27-interchain-accounts/types/keys.go b/modules/apps/27-interchain-accounts/types/keys.go
index 47df826dece..51841d0de0b 100644
--- a/modules/apps/27-interchain-accounts/types/keys.go
+++ b/modules/apps/27-interchain-accounts/types/keys.go
@@ -33,8 +33,8 @@ var (
 )
 
 // NewVersion returns a complete version string in the format: VersionPrefix + Delimter + AccAddress
-func NewAppVersion(versionPrefix, delimiter, addr string) string {
-	return fmt.Sprint(versionPrefix, delimiter, addr)
+func NewAppVersion(versionPrefix, accAddr string) string {
+	return fmt.Sprint(versionPrefix, Delimiter, accAddr)
 }
 
 // KeyActiveChannel creates and returns a new key used for active channels store operations
diff --git a/modules/apps/27-interchain-accounts/types/validate_test.go b/modules/apps/27-interchain-accounts/types/validate_test.go
index 3f7157ca696..aa1bb33c8ae 100644
--- a/modules/apps/27-interchain-accounts/types/validate_test.go
+++ b/modules/apps/27-interchain-accounts/types/validate_test.go
@@ -12,37 +12,37 @@ func (suite *TypesTestSuite) TestValidateVersion() {
 	}{
 		{
 			"success",
-			types.NewAppVersion(types.VersionPrefix, types.Delimiter, TestOwnerAddress),
+			types.NewAppVersion(types.VersionPrefix, TestOwnerAddress),
 			true,
 		},
 		{
-			"success - version only",
-			types.NewAppVersion(types.VersionPrefix, "", ""),
+			"success - version prefix only",
+			types.VersionPrefix,
 			true,
 		},
 		{
 			"invalid version",
-			types.NewAppVersion("ics27-5", types.Delimiter, TestOwnerAddress),
+			types.NewAppVersion("ics27-5", TestOwnerAddress),
 			false,
 		},
 		{
 			"invalid account address - empty",
-			types.NewAppVersion(types.VersionPrefix, types.Delimiter, ""),
+			types.NewAppVersion(types.VersionPrefix, ""),
 			false,
 		},
 		{
 			"invalid account address - exceeded character length",
-			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatltfwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
+			types.NewAppVersion(types.VersionPrefix, "ofwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatltfwafxhdmqcdbpzvrccxkidbunrwyyoboyctignpvthxbwxtmnzyfwhhywobaatlt"),
 			false,
 		},
 		{
 			"invalid account address - non alphanumeric characters",
-			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "-_-"),
+			types.NewAppVersion(types.VersionPrefix, "-_-"),
 			false,
 		},
 		{
 			"invalid account address - address contains additional delimiter",
-			types.NewAppVersion(types.VersionPrefix, types.Delimiter, "cosmos17dtl0mjt3t77kpu|hg2edqzjpszulwhgzuj9ljs"),
+			types.NewAppVersion(types.VersionPrefix, "cosmos17dtl0mjt3t77kpu|hg2edqzjpszulwhgzuj9ljs"),
 			false,
 		},
 	}

From 3d5baabf6b8128f190b8cb38276c513b0ec4a867 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Mon, 20 Sep 2021 16:05:00 +0200
Subject: [PATCH 16/17] Update
 modules/apps/27-interchain-accounts/keeper/handshake.go

Co-authored-by: Sean King <seantking@users.noreply.github.com>
---
 modules/apps/27-interchain-accounts/keeper/handshake.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/modules/apps/27-interchain-accounts/keeper/handshake.go b/modules/apps/27-interchain-accounts/keeper/handshake.go
index d3ea5de071a..bccd1be1a16 100644
--- a/modules/apps/27-interchain-accounts/keeper/handshake.go
+++ b/modules/apps/27-interchain-accounts/keeper/handshake.go
@@ -87,6 +87,7 @@ func (k Keeper) OnChanOpenTry(
 		return err
 	}
 
+        // Check to ensure that the version string contains the expected address generated from the Counterparty portID 
 	accAddr := types.GenerateAddress(counterparty.PortId)
 	parsedAddr := types.ParseAddressFromVersion(version)
 	if parsedAddr != accAddr.String() {

From f400bdc4298feda238eae083863685052cf8bbf5 Mon Sep 17 00:00:00 2001
From: Damian Nolan <damiannolan@gmail.com>
Date: Mon, 20 Sep 2021 16:15:44 +0200
Subject: [PATCH 17/17] updating ValidateVersion godoc

---
 modules/apps/27-interchain-accounts/types/validate.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/modules/apps/27-interchain-accounts/types/validate.go b/modules/apps/27-interchain-accounts/types/validate.go
index 596d0c467ae..691eb369e41 100644
--- a/modules/apps/27-interchain-accounts/types/validate.go
+++ b/modules/apps/27-interchain-accounts/types/validate.go
@@ -14,8 +14,11 @@ var DefaultMaxAddrLength = 128
 // strictly alphanumeric characters
 var IsValidAddr = regexp.MustCompile("^[a-zA-Z0-9]*$").MatchString
 
-// ValidateVersion performs basic validation of the provided ics27 version string
-// When no delimiter is present it compares against the expected version
+// ValidateVersion performs basic validation of the provided ics27 version string.
+// An ics27 version string may include an optional account address as per [TODO: Add spec when available]
+// ValidateVersion first attempts to split the version string using the standard delimiter, then asserts a supported
+// version prefix is included, followed by additional checks which enforce constraints on the optional account address.
+// When no delimiter is present, only the version prefix is validated
 func ValidateVersion(version string) error {
 	s := strings.Split(version, Delimiter)