diff --git a/x/btcbridge/keeper/deposit.go b/x/btcbridge/keeper/deposit.go
index ac35917b..d3c8d248 100644
--- a/x/btcbridge/keeper/deposit.go
+++ b/x/btcbridge/keeper/deposit.go
@@ -51,8 +51,8 @@ func (k Keeper) Mint(ctx sdk.Context, sender string, tx *btcutil.Tx, prevTx *btc
 
 	isRunes := edict != nil
 
-	// check if the sender is authorized to relay runes deposit
-	if isRunes && !k.IsAuthorizedNonBtcRelayer(ctx, sender) {
+	// check if the sender is trusted to relay runes deposit
+	if isRunes && !k.IsTrustedNonBtcRelayer(ctx, sender) {
 		return nil, types.ErrUnauthorizedNonBtcRelayer
 	}
 
diff --git a/x/btcbridge/keeper/msg_server.go b/x/btcbridge/keeper/msg_server.go
index 89b7bde9..78052efa 100644
--- a/x/btcbridge/keeper/msg_server.go
+++ b/x/btcbridge/keeper/msg_server.go
@@ -44,7 +44,7 @@ func (m msgServer) UpdateNonBtcRelayers(goCtx context.Context, msg *types.MsgUpd
 		return nil, err
 	}
 
-	if !m.IsAuthorizedNonBtcRelayer(ctx, msg.Sender) {
+	if !m.IsTrustedNonBtcRelayer(ctx, msg.Sender) {
 		return nil, types.ErrUnauthorizedNonBtcRelayer
 	}
 
diff --git a/x/btcbridge/keeper/params.go b/x/btcbridge/keeper/params.go
index f3e811da..a265965c 100644
--- a/x/btcbridge/keeper/params.go
+++ b/x/btcbridge/keeper/params.go
@@ -24,8 +24,8 @@ func (k Keeper) ProtocolWithdrawFeeEnabled(ctx sdk.Context) bool {
 	return k.GetParams(ctx).ProtocolFees.WithdrawFee > 0
 }
 
-// IsAuthorizedNonBtcRelayer returns true if the given address is an authorized non-btc relayer, false otherwise
-func (k Keeper) IsAuthorizedNonBtcRelayer(ctx sdk.Context, addr string) bool {
+// IsTrustedNonBtcRelayer returns true if the given address is a trusted non-btc relayer, false otherwise
+func (k Keeper) IsTrustedNonBtcRelayer(ctx sdk.Context, addr string) bool {
 	for _, relayer := range k.GetParams(ctx).NonBtcRelayers {
 		if relayer == addr {
 			return true
diff --git a/x/btcbridge/keeper/withdraw.go b/x/btcbridge/keeper/withdraw.go
index fd99d2c5..d6cbe247 100644
--- a/x/btcbridge/keeper/withdraw.go
+++ b/x/btcbridge/keeper/withdraw.go
@@ -166,11 +166,12 @@ func (k Keeper) GetWithdrawRequest(ctx sdk.Context, sequence uint64) *types.Bitc
 func (k Keeper) GetWithdrawRequestByTxHash(ctx sdk.Context, hash string) *types.BitcoinWithdrawRequest {
 	store := ctx.KVStore(k.storeKey)
 
-	var withdrawRequest types.BitcoinWithdrawRequest
 	bz := store.Get(types.BtcWithdrawRequestByTxHashKey(hash))
-	k.cdc.MustUnmarshal(bz, &withdrawRequest)
+	if bz != nil {
+		return k.GetWithdrawRequest(ctx, sdk.BigEndianToUint64(bz))
+	}
 
-	return &withdrawRequest
+	return nil
 }
 
 // SetWithdrawRequest sets the withdrawal request
@@ -180,7 +181,7 @@ func (k Keeper) SetWithdrawRequest(ctx sdk.Context, withdrawRequest *types.Bitco
 	bz := k.cdc.MustMarshal(withdrawRequest)
 
 	store.Set(types.BtcWithdrawRequestKey(withdrawRequest.Sequence), bz)
-	store.Set(types.BtcWithdrawRequestByTxHashKey(withdrawRequest.Txid), types.Int64ToBytes(withdrawRequest.Sequence))
+	store.Set(types.BtcWithdrawRequestByTxHashKey(withdrawRequest.Txid), sdk.Uint64ToBigEndian(withdrawRequest.Sequence))
 }
 
 // IterateWithdrawRequests iterates through all withdrawal requests
@@ -281,11 +282,15 @@ func (k Keeper) LockAssets(ctx sdk.Context, req *types.BitcoinWithdrawRequest, a
 		return err
 	}
 
-	if err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, sdk.MustAccAddressFromBech32(req.Address), types.ModuleName, sdk.NewCoins(amount, btcNetworkFee)); err != nil {
+	if err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, sdk.MustAccAddressFromBech32(req.Address), types.ModuleName, sdk.NewCoins(amount)); err != nil {
+		return err
+	}
+
+	if err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, sdk.MustAccAddressFromBech32(req.Address), types.ModuleName, sdk.NewCoins(btcNetworkFee)); err != nil {
 		return err
 	}
 
-	// lock the assets sent to the module account, which will be burned when the withdrawal tx is relayed back
+	// mark locked assets which will be burned when the withdrawal tx is relayed back
 	k.lockAssets(ctx, req.Txid, amount, btcNetworkFee)
 
 	return nil
diff --git a/x/btcbridge/types/params.go b/x/btcbridge/types/params.go
index 690c61e9..b37ae292 100644
--- a/x/btcbridge/types/params.go
+++ b/x/btcbridge/types/params.go
@@ -74,17 +74,18 @@ func (p Params) Validate() error {
 	return validateTSSParams(&p.TssParams)
 }
 
-// SelectVaultByAddress returns the vault by the address
+// SelectVaultByAddress returns the vault by the given address
 func SelectVaultByAddress(vaults []*Vault, address string) *Vault {
 	for _, v := range vaults {
 		if v.Address == address {
 			return v
 		}
 	}
+
 	return nil
 }
 
-// SelectVaultByPubKey returns the vault by the public key
+// SelectVaultByPubKey returns the vault by the given public key
 func SelectVaultByPubKey(vaults []*Vault, pubKey string) *Vault {
 	for _, v := range vaults {
 		if v.PubKey == pubKey {
@@ -110,7 +111,7 @@ func SelectVaultByAssetType(vaults []*Vault, assetType AssetType) *Vault {
 	return nil
 }
 
-// SelectVaultByPkScript returns the vault by the pk script
+// SelectVaultByPkScript returns the vault by the given pk script for convenience
 func SelectVaultByPkScript(vaults []*Vault, pkScript []byte) *Vault {
 	chainCfg := sdk.GetConfig().GetBtcChainCfg()
 
@@ -133,6 +134,7 @@ func SelectVaultByPkScript(vaults []*Vault, pkScript []byte) *Vault {
 	return nil
 }
 
+// validateNonBtcRelayers validates the given relayers
 func validateNonBtcRelayers(relayers []string) error {
 	if len(relayers) == 0 {
 		return ErrInvalidParams