BTCStaking: generalise KVStore schema and parameters for restaking an…

…d multisig covenant (#108)

cmd/babylond/cmd/flags.go

@@ -28,7 +28,7 @@ const (
  flagBlocksPerYear = "blocks-per-year"
  flagGenesisTime = "genesis-time"
  flagBlockGasLimit = "block-gas-limit"
- flagCovenantPk = "covenant-pk"
+ flagCovenantPk = "covenant-pk" // TODO: multisig covenant
  flagSlashingAddress = "slashing-address"
  flagMinSlashingFee = "min-slashing-fee-sat"
  flagSlashingRate = "slashing-rate"
@@ -75,7 +75,7 @@ func addGenesisFlags(cmd *cobra.Command) {
  cmd.Flags().String(flagBaseBtcHeaderHex, "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a45068653ffff7f2002000000", "Hex of the base Bitcoin header.")
  cmd.Flags().Uint64(flagBaseBtcHeaderHeight, 0, "Height of the base Bitcoin header.")
  // btcstaking args
- cmd.Flags().String(flagCovenantPk, btcstypes.DefaultParams().CovenantPk.MarshalHex(), "Bitcoin staking covenant public key")
+ cmd.Flags().String(flagCovenantPk, btcstypes.DefaultParams().CovenantPks[0].MarshalHex(), "Bitcoin staking covenant public key")
  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/babylond/cmd/genesis.go

@@ -305,10 +305,12 @@ func TestnetGenesisParams(maxActiveValidators uint32, btcConfirmationDepth uint6
  genParams.BtclightclientBaseBtcHeader = *baseBtcHeaderInfo
 
  genParams.BtcstakingParams = btcstakingtypes.DefaultParams()
- genParams.BtcstakingParams.CovenantPk, err = bbn.NewBIP340PubKeyFromHex(covenantPk)
+ covenantPK, err := bbn.NewBIP340PubKeyFromHex(covenantPk)
  if err != nil {
  panic(err)
  }
+ genParams.BtcstakingParams.CovenantPks = []bbn.BIP340PubKey{*covenantPK}
+ genParams.BtcstakingParams.CovenantQuorum = 1 // TODO: multisig covenant
  genParams.BtcstakingParams.SlashingAddress = slashingAddress
  genParams.BtcstakingParams.MinSlashingTxFeeSat = minSlashingFee
  genParams.BtcstakingParams.MinCommissionRate = minCommissionRate

proto/babylon/btcstaking/v1/btcstaking.proto

@@ -63,10 +63,11 @@ message BTCDelegation {
  bytes btc_pk = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
  // pop is the proof of possession of babylon_pk and btc_pk
  ProofOfPossession pop = 3;
- // val_btc_pk is the Bitcoin secp256k1 PK of the BTC validator that
+ // val_btc_pk_list is the list of BIP-340 PKs of the BTC validators that
  // this BTC delegation delegates to
- // the PK follows encoding in BIP-340 spec
- bytes val_btc_pk = 4 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ // If there is more than 1 PKs, then this means the delegation is restaked
+ // to multiple BTC validators
+ repeated bytes val_btc_pk_list = 4 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
  // start_height is the start BTC height of the BTC delegation
  // it is the start BTC height of the timelock
  uint64 start_height = 5;
@@ -89,6 +90,7 @@ message BTCDelegation {
  // covenant_sig is the signature signature on the slashing tx
  // by the covenant (i.e., SK corresponding to covenant_pk in params)
  // It will be a part of the witness for the staking tx output.
+ // TODO: change to a set of (covenant PK, covenant adaptor signature) tuples
  bytes covenant_sig = 11 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
 
  // if this object is present it menans that staker requested undelegation, and whole
@@ -115,15 +117,18 @@ message BTCUndelegation {
  // covenant_slashing_sig is the signature on the slashing tx
  // by the covenant (i.e., SK corresponding to covenant_pk in params)
  // It must be provided after processing undelagate message by Babylon
+ // TODO: change to a set of (covenant PK, covenant adaptor signature) tuples
  bytes covenant_slashing_sig = 4 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
  // covenant_unbonding_sig is the signature on the unbonding tx
  // by the covenant (i.e., SK corresponding to covenant_pk in params)
  // It must be provided after processing undelagate message by Babylon and after
  // validator sig will be provided by validator
+ // TODO: change to a set of (covenant PK, covenant Schnorr signature) tuples
  bytes covenant_unbonding_sig = 5 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
  // validator_unbonding_sig is the signature on the unbonding tx
  // by the validator (i.e., SK corresponding to covenant_pk in params)
  // It must be provided after processing undelagate message by Babylon
+ // TODO: this is no longer needed
  bytes validator_unbonding_sig = 6 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
 }
 
@@ -139,11 +144,13 @@ message BTCUndelegationInfo {
  // by the validator (i.e., SK corresponding to the pk of the validator that the staker delegates to)
  // It must be provided after processing undelagate message by Babylon
  // It will be nil if validator didn't sign it yet
+ // TODO: this is no longer needed
  bytes validator_unbonding_sig = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
 
  // covenant_unbonding_sig is the signature on the unbonding tx
  // by the covenant (i.e., SK corresponding to covenant_pk in params)
  // it will be nil if covenant didn't sign it yet
+ // TODO: change to a set of (covenant PK, covenant Schnorr signature) tuples
  bytes covenant_unbonding_sig = 3 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
 }
 
@@ -190,3 +197,8 @@ enum BTCDelegationStatus {
  ANY = 4;
 }
 
+// SignatureInfo is a BIP-340 signature together with its signer's BIP-340 PK
+message SignatureInfo {
+ bytes pk = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ bytes sig = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340Signature" ];
+}

proto/babylon/btcstaking/v1/events.proto

@@ -24,10 +24,11 @@ message EventUnbondingBTCDelegation {
  // btc_pk is the Bitcoin secp256k1 PK of this BTC delegation
  // the PK follows encoding in BIP-340 spec
  bytes btc_pk = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
- // val_btc_pk is the Bitcoin secp256k1 PK of the BTC validator that
+ // val_btc_pk_list is the list of BIP-340 PKs of the BTC validators that
  // this BTC delegation delegates to
- // the PK follows encoding in BIP-340 spec
- bytes val_btc_pk = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ // If there is more than 1 PKs, then this means the delegation is restaked
+ // to multiple BTC validators
+ repeated bytes val_btc_pk_list = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
  // staking_tx_hash is the hash of the staking tx.
  // (val_pk, del_pk, staking_tx_hash) uniquely identifies a BTC delegation
  string staking_tx_hash = 3;
@@ -41,10 +42,11 @@ message EventUnbondedBTCDelegation {
  // btc_pk is the Bitcoin secp256k1 PK of this BTC delegation
  // the PK follows encoding in BIP-340 spec
  bytes btc_pk = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
- // val_btc_pk is the Bitcoin secp256k1 PK of the BTC validator that
+ // val_btc_pk_list is the list of BIP-340 PKs of the BTC validators that
  // this BTC delegation delegates to
- // the PK follows encoding in BIP-340 spec
- bytes val_btc_pk = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ // If there is more than 1 PKs, then this means the delegation is restaked
+ // to multiple BTC validators
+ repeated bytes val_btc_pk_list = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
  // staking_tx_hash is the hash of the staking tx.
  // (val_pk, del_pk, staking_tx_hash) uniquely identifies a BTC delegation
  string staking_tx_hash = 3;

proto/babylon/btcstaking/v1/params.proto

@@ -10,28 +10,31 @@ option go_package = "github.com/babylonchain/babylon/x/btcstaking/types";
 message Params {
  option (gogoproto.goproto_stringer) = false;
 
- // covenant_pk is the public key of covenant
- // the PK follows encoding in BIP-340 spec on Bitcoin
- bytes covenant_pk = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ // covenant_pks is the list of public keys held by the covenant committee
+ // each PK follows encoding in BIP-340 spec on Bitcoin
+ repeated bytes covenant_pks = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ // covenant_quorum is the minimum number of signatures needed for the covenant
+ // multisignature 
+ uint32 covenant_quorum = 2;
  // slashing address is the address that the slashed BTC goes to
  // the address is in string on Bitcoin
- string slashing_address = 2;
+ string slashing_address = 3;
  // 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;
+ int64 min_slashing_tx_fee_sat = 4;
  // min_commission_rate is the chain-wide minimum commission rate that a validator can charge their delegators
- string min_commission_rate = 4 [
+ string min_commission_rate = 5 [
  (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 [
+ string slashing_rate = 6 [
  (cosmos_proto.scalar) = "cosmos.Dec",
  (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
  (gogoproto.nullable) = false
  ];
  // max_active_btc_validators is the maximum number of active BTC validators in the BTC staking protocol
- uint32 max_active_btc_validators = 6;
+ uint32 max_active_btc_validators = 7;
 }

proto/babylon/btcstaking/v1/query.proto

@@ -222,10 +222,9 @@ message QueryBTCDelegationResponse {
  // btc_pk is the Bitcoin secp256k1 PK of this BTC delegation
  // the PK follows encoding in BIP-340 spec
  bytes btc_pk = 1 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
- // val_btc_pk is the Bitcoin secp256k1 PK of the BTC validator that
+ // val_btc_pk_list is the list of BIP-340 PKs of the BTC validators that
  // this BTC delegation delegates to
- // the PK follows encoding in BIP-340 spec
- bytes val_btc_pk = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
+ repeated bytes val_btc_pk_list = 2 [ (gogoproto.customtype) = "github.com/babylonchain/babylon/types.BIP340PubKey" ];
  // start_height is the start BTC height of the BTC delegation
  // it is the start BTC height of the timelock
  uint64 start_height = 3;

test/e2e/btc_staking_e2e_test.go

@@ -100,6 +100,11 @@ func (s *BTCStakingTestSuite) Test1CreateBTCValidatorAndDelegation() {
  */
  // BTC staking params, BTC delegation key pairs and PoP
  params := nonValidatorNode.QueryBTCStakingParams()
+ // get covenant BTC PKs
+ covenantBTCPKs := []*btcec.PublicKey{}
+ for _, covenantPK := range params.CovenantPks {
+ covenantBTCPKs = append(covenantBTCPKs, covenantPK.MustToBTCPK())
+ }
  // NOTE: we use the node's secret key as Babylon secret key for the BTC delegation
  delBabylonSK := nonValidatorNode.SecretKey
  pop, err := bstypes.NewPoP(delBabylonSK, delBTCSK)
@@ -110,8 +115,8 @@ func (s *BTCStakingTestSuite) Test1CreateBTCValidatorAndDelegation() {
  r,
  net,
  delBTCSK,
- btcVal.BtcPk.MustToBTCPK(),
- params.CovenantPk.MustToBTCPK(),
+ []*btcec.PublicKey{btcVal.BtcPk.MustToBTCPK()},
+ covenantBTCPKs,
  stakingTimeBlocks,
  stakingValue,
  params.SlashingAddress, changeAddress.String(),
@@ -386,6 +391,11 @@ func (s *BTCStakingTestSuite) Test5SubmitStakerUnbonding() {
 
  // params for covenantPk and slashing address
  params := nonValidatorNode.QueryBTCStakingParams()
+ // get covenant BTC PKs
+ covenantBTCPKs := []*btcec.PublicKey{}
+ for _, covenantPK := range params.CovenantPks {
+ covenantBTCPKs = append(covenantBTCPKs, covenantPK.MustToBTCPK())
+ }
 
  stakingTx := activeDel.StakingTx
  stakingMsgTx, err := stakingTx.ToMsgTx()
@@ -404,8 +414,8 @@ func (s *BTCStakingTestSuite) Test5SubmitStakerUnbonding() {
  r,
  net,
  delBTCSK,
- btcVal.BtcPk.MustToBTCPK(),
- params.CovenantPk.MustToBTCPK(),
+ []*btcec.PublicKey{btcVal.BtcPk.MustToBTCPK()},
+ covenantBTCPKs,
  wire.NewOutPoint(stakingTxChainHash, uint32(stakingOutputIdx)),
  initialization.BabylonBtcFinalizationPeriod+1,
  stakingValue-fee,

testutil/datagen/btcstaking.go

@@ -65,20 +65,29 @@ func GenRandomBTCValidatorWithBTCBabylonSKs(r *rand.Rand, btcSK *btcec.PrivateKe
 
 func GenRandomBTCDelegation(
  r *rand.Rand,
- valBTCPK *bbn.BIP340PubKey,
+ valBTCPKs []bbn.BIP340PubKey,
  delSK *btcec.PrivateKey,
- covenantSK *btcec.PrivateKey,
+ covenantSKs []*btcec.PrivateKey,
  slashingAddress, changeAddress string,
  startHeight, endHeight, totalSat uint64,
  slashingRate sdk.Dec,
 ) (*bstypes.BTCDelegation, error) {
  net := &chaincfg.SimNetParams
  delPK := delSK.PubKey()
  delBTCPK := bbn.NewBIP340PubKeyFromBTCPK(delPK)
- covenantBTCPK := covenantSK.PubKey()
- valPK, err := valBTCPK.ToBTCPK()
- if err != nil {
- return nil, err
+ // list of covenant PKs
+ covenantBTCPKs := []*btcec.PublicKey{}
+ for _, covenantSK := range covenantSKs {
+ covenantBTCPKs = append(covenantBTCPKs, covenantSK.PubKey())
+ }
+ // list of validator PKs
+ valPKs := []*btcec.PublicKey{}
+ for _, valBTCPK := range valBTCPKs {
+ valPK, err := valBTCPK.ToBTCPK()
+ if err != nil {
+ return nil, err
+ }
+ valPKs = append(valPKs, valPK)
  }
 
  // BTC delegation Babylon key pairs
@@ -100,8 +109,8 @@ func GenRandomBTCDelegation(
  r,
  net,
  delSK,
- valPK,
- covenantBTCPK,
+ valPKs,
+ covenantBTCPKs,
  uint16(endHeight-startHeight),
  int64(totalSat),
  slashingAddress, changeAddress,
@@ -115,7 +124,8 @@ func GenRandomBTCDelegation(
  if err != nil {
  return nil, err
  }
- covenantSig, err := slashingTx.Sign(stakingMsgTx, stakingTx.Script, covenantSK, net)
+ // TODO: covenant multisig
+ covenantSig, err := slashingTx.Sign(stakingMsgTx, stakingTx.Script, covenantSKs[0], net)
  if err != nil {
  return nil, err
  }
@@ -128,7 +138,7 @@ func GenRandomBTCDelegation(
  BabylonPk: secp256k1PK,
  BtcPk: delBTCPK,
  Pop: pop,
- ValBtcPk: valBTCPK,
+ ValBtcPkList: valBTCPKs,
  StartHeight: startHeight,
  EndHeight: endHeight,
  TotalSat: totalSat,
@@ -144,18 +154,19 @@ func GenBTCStakingSlashingTxWithOutPoint(
  btcNet *chaincfg.Params,
  outPoint *wire.OutPoint,
  stakerSK *btcec.PrivateKey,
- validatorPK *btcec.PublicKey,
- covenantPK *btcec.PublicKey,
+ validatorPKs []*btcec.PublicKey,
+ covenantPKs []*btcec.PublicKey,
  stakingTimeBlocks uint16,
  stakingValue int64,
  slashingAddress, changeAddress string,
  slashingRate sdk.Dec,
  withChange bool,
 ) (*bstypes.BabylonBTCTaprootTx, *bstypes.BTCSlashingTx, error) {
+ // TODO: covenant multisig
  stakingOutput, stakingScript, err := btcstaking.BuildStakingOutput(
  stakerSK.PubKey(),
- validatorPK,
- covenantPK,
+ validatorPKs[0],
+ covenantPKs[0],
  stakingTimeBlocks,
  btcutil.Amount(stakingValue),
  btcNet,
@@ -226,8 +237,8 @@ func GenBTCStakingSlashingTx(
  r *rand.Rand,
  btcNet *chaincfg.Params,
  stakerSK *btcec.PrivateKey,
- validatorPK *btcec.PublicKey,
- covenantPK *btcec.PublicKey,
+ validatorPKs []*btcec.PublicKey,
+ covenantPKs []*btcec.PublicKey,
  stakingTimeBlocks uint16,
  stakingValue int64,
  slashingAddress, changeAddress string,
@@ -241,8 +252,8 @@ func GenBTCStakingSlashingTx(
  btcNet,
  outPoint,
  stakerSK,
- validatorPK,
- covenantPK,
+ validatorPKs,
+ covenantPKs,
  stakingTimeBlocks,
  stakingValue,
  slashingAddress, changeAddress,
@@ -254,8 +265,8 @@ func GenBTCUnbondingSlashingTx(
  r *rand.Rand,
  btcNet *chaincfg.Params,
  stakerSK *btcec.PrivateKey,
- validatorPK *btcec.PublicKey,
- covenantPK *btcec.PublicKey,
+ validatorPKs []*btcec.PublicKey,
+ covenantPKs []*btcec.PublicKey,
  stakingTransactionOutpoint *wire.OutPoint,
  stakingTimeBlocks uint16,
  stakingValue int64,
@@ -267,8 +278,8 @@ func GenBTCUnbondingSlashingTx(
  btcNet,
  stakingTransactionOutpoint,
  stakerSK,
- validatorPK,
- covenantPK,
+ validatorPKs,
+ covenantPKs,
  stakingTimeBlocks,
  stakingValue,
  slashingAddress, changeAddress,