feat: Add SlashingRate param in btcstaking module (#95)

* proto def

* proto def

* genesis setup

* fix

* more comments

* comprehensive comments

* improve checks

* fix checks

* change slashing_percentage data type to cosmos.Dec

* fix slashing_percentage usages to cosmos.Dec

* fix validation check for default params

* fix checks and tests

* change default percentage to 10

* fix template

* change slashing percentage to slashing rate in proto

* replace usages with slashingRate

* fix comments and checks

* fix error message

cmd/babylond/cmd/flags.go

@@ -1,9 +1,10 @@
 package cmd
 
 import (
- sdk "github.com/cosmos/cosmos-sdk/types"
  "time"
 
+ sdk "github.com/cosmos/cosmos-sdk/types"
+
  babylonApp "github.com/babylonchain/babylon/app"
  btcctypes "github.com/babylonchain/babylon/x/btccheckpoint/types"
  btcstypes "github.com/babylonchain/babylon/x/btcstaking/types"
@@ -30,6 +31,7 @@ const (
  flagJuryPk = "jury-pk"
  flagSlashingAddress = "slashing-address"
  flagMinSlashingFee = "min-slashing-fee-sat"
+ flagSlashingRate = "slashing-rate"
  flagMinPubRand = "min-pub-rand"
  flagMinCommissionRate = "min-commission-rate"
 )
@@ -53,6 +55,7 @@ type GenesisCLIArgs struct {
  JuryPK string
  SlashingAddress string
  MinSlashingTransactionFeeSat int64
+ SlashingRate sdk.Dec
  MinPubRand uint64
  MinCommissionRate sdk.Dec
 }
@@ -76,6 +79,7 @@ func addGenesisFlags(cmd *cobra.Command) {
  cmd.Flags().String(flagSlashingAddress, btcstypes.DefaultParams().SlashingAddress, "Bitcoin staking slashing address")
  cmd.Flags().Int64(flagMinSlashingFee, 1000, "Bitcoin staking minimum slashing fee")
  cmd.Flags().String(flagMinCommissionRate, "0", "Bitcoin staking validator minimum commission rate")
+ cmd.Flags().String(flagSlashingRate, "0.1", "Bitcoin staking slashing rate")
  // finality args
  cmd.Flags().Uint64(flagMinPubRand, 100, "Bitcoin staking minimum public randomness commit")
  // inflation args
@@ -103,6 +107,7 @@ func parseGenesisFlags(cmd *cobra.Command) *GenesisCLIArgs {
  slashingAddress, _ := cmd.Flags().GetString(flagSlashingAddress)
  minSlashingFee, _ := cmd.Flags().GetInt64(flagMinSlashingFee)
  minCommissionRate, _ := cmd.Flags().GetString(flagMinCommissionRate)
+ slashingRate, _ := cmd.Flags().GetString(flagSlashingRate)
  minPubRand, _ := cmd.Flags().GetUint64(flagMinPubRand)
  genesisTimeUnix, _ := cmd.Flags().GetInt64(flagGenesisTime)
  inflationRateChange, _ := cmd.Flags().GetFloat64(flagInflationRateChange)
@@ -131,6 +136,7 @@ func parseGenesisFlags(cmd *cobra.Command) *GenesisCLIArgs {
  SlashingAddress: slashingAddress,
  MinSlashingTransactionFeeSat: minSlashingFee,
  MinCommissionRate: sdk.MustNewDecFromStr(minCommissionRate),
+ SlashingRate: sdk.MustNewDecFromStr(slashingRate),
  MinPubRand: minPubRand,
  GenesisTime: genesisTime,
  InflationRateChange: inflationRateChange,

cmd/babylond/cmd/genesis.go

@@ -3,9 +3,10 @@ package cmd
 import (
  "encoding/json"
  "fmt"
+ "time"
+
  btcstakingtypes "github.com/babylonchain/babylon/x/btcstaking/types"
  finalitytypes "github.com/babylonchain/babylon/x/finality/types"
- "time"
 
  appparams "github.com/babylonchain/babylon/app/params"
  bbn "github.com/babylonchain/babylon/types"
@@ -69,7 +70,8 @@ Example:
  genesisCliArgs.EpochInterval, genesisCliArgs.BaseBtcHeaderHex,
  genesisCliArgs.BaseBtcHeaderHeight, genesisCliArgs.JuryPK,
  genesisCliArgs.SlashingAddress, genesisCliArgs.MinSlashingTransactionFeeSat,
- genesisCliArgs.MinCommissionRate, genesisCliArgs.MinPubRand, genesisCliArgs.InflationRateChange,
+ genesisCliArgs.MinCommissionRate, genesisCliArgs.SlashingRate,
+ genesisCliArgs.MinPubRand, genesisCliArgs.InflationRateChange,
  genesisCliArgs.InflationMin, genesisCliArgs.InflationMax, genesisCliArgs.GoalBonded,
  genesisCliArgs.BlocksPerYear, genesisCliArgs.GenesisTime, genesisCliArgs.BlockGasLimit)
  } else if network == "mainnet" {
@@ -229,7 +231,7 @@ type GenesisParams struct {
 func TestnetGenesisParams(maxActiveValidators uint32, btcConfirmationDepth uint64,
  btcFinalizationTimeout uint64, checkpointTag string, epochInterval uint64, baseBtcHeaderHex string,
  baseBtcHeaderHeight uint64, juryPk string, slashingAddress string, minSlashingFee int64,
- minCommissionRate sdk.Dec, minPubRand uint64, inflationRateChange float64,
+ minCommissionRate sdk.Dec, slashingRate sdk.Dec, minPubRand uint64, inflationRateChange float64,
  inflationMin float64, inflationMax float64, goalBonded float64,
  blocksPerYear uint64, genesisTime time.Time, blockGasLimit int64) GenesisParams {
 
@@ -310,6 +312,7 @@ func TestnetGenesisParams(maxActiveValidators uint32, btcConfirmationDepth uint6
  genParams.BtcstakingParams.SlashingAddress = slashingAddress
  genParams.BtcstakingParams.MinSlashingTxFeeSat = minSlashingFee
  genParams.BtcstakingParams.MinCommissionRate = minCommissionRate
+ genParams.BtcstakingParams.SlashingRate = slashingRate
  if err := genParams.BtcstakingParams.Validate(); err != nil {
  panic(err)
  }

cmd/babylond/cmd/testnet.go

@@ -99,7 +99,8 @@ Example:
  genesisCliArgs.BtcConfirmationDepth, genesisCliArgs.BtcFinalizationTimeout, genesisCliArgs.CheckpointTag,
  genesisCliArgs.EpochInterval, genesisCliArgs.BaseBtcHeaderHex, genesisCliArgs.BaseBtcHeaderHeight,
  genesisCliArgs.JuryPK, genesisCliArgs.SlashingAddress, genesisCliArgs.MinSlashingTransactionFeeSat,
- genesisCliArgs.MinCommissionRate, genesisCliArgs.MinPubRand, genesisCliArgs.InflationRateChange, genesisCliArgs.InflationMin,
+ genesisCliArgs.MinCommissionRate, genesisCliArgs.SlashingRate, genesisCliArgs.MinPubRand,
+ genesisCliArgs.InflationRateChange, genesisCliArgs.InflationMin,
  genesisCliArgs.InflationMax, genesisCliArgs.GoalBonded, genesisCliArgs.BlocksPerYear,
  genesisCliArgs.GenesisTime, genesisCliArgs.BlockGasLimit)
 

proto/babylon/btcstaking/v1/params.proto

@@ -2,6 +2,7 @@ syntax = "proto3";
 package babylon.btcstaking.v1;
 
 import "gogoproto/gogo.proto";
+import "cosmos_proto/cosmos.proto";
 
 option go_package = "github.com/babylonchain/babylon/x/btcstaking/types";
 
@@ -15,7 +16,7 @@ message Params {
  // slashing address is the address that the slashed BTC goes to
  // the address is in string on Bitcoin
  string slashing_address = 2;
- // min_slashing_tx_fee_sat is the minimum amount of tx fee (quantified 
+ // min_slashing_tx_fee_sat is the minimum amount of tx fee (quantified
  // in Satoshi) needed for the pre-signed slashing tx
  // TODO: change to satoshi per byte?
  int64 min_slashing_tx_fee_sat = 3;
@@ -24,4 +25,11 @@ message Params {
  (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
  (gogoproto.nullable) = false
  ];
+ // slashing_rate determines the portion of the staked amount to be slashed,
+ // expressed as a decimal (e.g., 0.5 for 50%).
+ string slashing_rate = 5 [
+ (cosmos_proto.scalar) = "cosmos.Dec",
+ (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
+ (gogoproto.nullable) = false
+ ];
 }

x/btcstaking/keeper/msg_server_test.go

@@ -100,6 +100,7 @@ func getJuryInfo(t *testing.T,
  SlashingAddress: slashingAddr.String(),
  MinSlashingTxFeeSat: 10,
  MinCommissionRate: sdk.MustNewDecFromStr("0.01"),
+ SlashingRate: sdk.MustNewDecFromStr("0.1"),
  })
  require.NoError(t, err)
  return jurySK, juryPK, slashingAddr
@@ -406,6 +407,7 @@ func TestDoNotAllowDelegationWithoutValidator(t *testing.T) {
  SlashingAddress: slashingAddr.String(),
  MinSlashingTxFeeSat: 10,
  MinCommissionRate: sdk.MustNewDecFromStr("0.01"),
+ SlashingRate: sdk.MustNewDecFromStr("0.1"),
  })
  require.NoError(t, err)
 

x/btcstaking/types/genesis_test.go

@@ -1,9 +1,10 @@
 package types_test
 
 import (
- sdkmath "cosmossdk.io/math"
  "testing"
 
+ sdkmath "cosmossdk.io/math"
+
  "github.com/babylonchain/babylon/x/btcstaking/types"
  "github.com/stretchr/testify/require"
 )
@@ -27,10 +28,24 @@ func TestGenesisState_Validate(t *testing.T) {
  SlashingAddress: types.DefaultParams().SlashingAddress,
  MinSlashingTxFeeSat: 500,
  MinCommissionRate: sdkmath.LegacyMustNewDecFromStr("0.5"),
+ SlashingRate: sdkmath.LegacyMustNewDecFromStr("0.1"),
  },
  },
  valid: true,
  },
+ {
+ desc: "invalid slashing rate in genesis",
+ genState: &types.GenesisState{
+ Params: types.Params{
+ JuryPk: types.DefaultParams().JuryPk,
+ SlashingAddress: types.DefaultParams().SlashingAddress,
+ MinSlashingTxFeeSat: 500,
+ MinCommissionRate: sdkmath.LegacyMustNewDecFromStr("0.5"),
+ SlashingRate: sdkmath.LegacyZeroDec(), // invalid slashing rate
+ },
+ },
+ valid: false,
+ },
  }
  for _, tc := range tests {
  t.Run(tc.desc, func(t *testing.T) {

x/btcstaking/types/params.go

@@ -1,8 +1,9 @@
 package types
 
 import (
- "cosmossdk.io/math"
  "fmt"
+
+ "cosmossdk.io/math"
  bbn "github.com/babylonchain/babylon/types"
  "github.com/btcsuite/btcd/btcec/v2"
  "github.com/btcsuite/btcd/btcutil"
@@ -43,6 +44,8 @@ func DefaultParams() Params {
  SlashingAddress: defaultSlashingAddress(),
  MinSlashingTxFeeSat: 1000,
  MinCommissionRate: math.LegacyZeroDec(),
+ // The Default slashing rate is 0.1 i.e., 10% of the total staked BTC will be burned.
+ SlashingRate: math.LegacyNewDecWithPrec(1, 1), // 1 * 10^{-1} = 0.1
  }
 }
 
@@ -73,6 +76,14 @@ func validateMinCommissionRate(rate sdk.Dec) error {
  return nil
 }
 
+// validateSlashingRate checks if the slashing rate is within the valid range (0, 1].
+func validateSlashingRate(slashingRate sdk.Dec) error {
+ if slashingRate.LTE(math.LegacyZeroDec()) || slashingRate.GT(math.LegacyOneDec()) {
+ return fmt.Errorf("slashing rate must be in the range (0, 1] i.e., 0 exclusive and 1 inclusive")
+ }
+ return nil
+}
+
 // Validate validates the set of params
 func (p Params) Validate() error {
  if err := validateMinSlashingTxFeeSat(p.MinSlashingTxFeeSat); err != nil {
@@ -81,6 +92,9 @@ func (p Params) Validate() error {
  if err := validateMinCommissionRate(p.MinCommissionRate); err != nil {
  return err
  }
+ if err := validateSlashingRate(p.SlashingRate); err != nil {
+ return err
+ }
  return nil
 }