diff --git a/crypto/signature.go b/crypto/signature.go
index 706e019..d4f117f 100644
--- a/crypto/signature.go
+++ b/crypto/signature.go
@@ -60,7 +60,7 @@ func VerifySignedMessageByOwner(
 		}
 		res, err := signerVerification.IsValidSignature(&bind.CallOpts{
 			Context: context.Background(),
-		}, hash[:], signature)
+		}, hash, signature)
 		if err != nil {
 			return err
 		}
diff --git a/eip1271/abi.abi b/eip1271/abi.abi
index 42f30fa..c771f56 100644
--- a/eip1271/abi.abi
+++ b/eip1271/abi.abi
@@ -3,8 +3,8 @@
     "constant": true,
     "inputs": [
       {
-        "name": "_data",
-        "type": "bytes"
+        "name": "_hash",
+        "type": "bytes32"
       },
       {
         "name": "_signature",
diff --git a/eip1271/eip1271.go b/eip1271/eip1271.go
index 7aceafe..56e62f7 100644
--- a/eip1271/eip1271.go
+++ b/eip1271/eip1271.go
@@ -31,7 +31,7 @@ var (
 
 // Eip1271MetaData contains all meta data concerning the Eip1271 contract.
 var Eip1271MetaData = &bind.MetaData{
-	ABI: "[{\"constant\":true,\"inputs\":[{\"name\":\"_data\",\"type\":\"bytes\"},{\"name\":\"_signature\",\"type\":\"bytes\"}],\"name\":\"isValidSignature\",\"outputs\":[{\"name\":\"magicValue\",\"type\":\"bytes4\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"}]",
+	ABI: "[{\"constant\":true,\"inputs\":[{\"name\":\"_hash\",\"type\":\"bytes32\"},{\"name\":\"_signature\",\"type\":\"bytes\"}],\"name\":\"isValidSignature\",\"outputs\":[{\"name\":\"magicValue\",\"type\":\"bytes4\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"}]",
 }
 
 // Eip1271ABI is the input ABI used to generate the binding from.
@@ -180,12 +180,12 @@ func (_Eip1271 *Eip1271TransactorRaw) Transact(opts *bind.TransactOpts, method s
 	return _Eip1271.Contract.contract.Transact(opts, method, params...)
 }
 
-// IsValidSignature is a free data retrieval call binding the contract method 0x20c13b0b.
+// IsValidSignature is a free data retrieval call binding the contract method 0x1626ba7e.
 //
-// Solidity: function isValidSignature(bytes _data, bytes _signature) view returns(bytes4 magicValue)
-func (_Eip1271 *Eip1271Caller) IsValidSignature(opts *bind.CallOpts, _data []byte, _signature []byte) ([4]byte, error) {
+// Solidity: function isValidSignature(bytes32 _hash, bytes _signature) view returns(bytes4 magicValue)
+func (_Eip1271 *Eip1271Caller) IsValidSignature(opts *bind.CallOpts, _hash [32]byte, _signature []byte) ([4]byte, error) {
 	var out []interface{}
-	err := _Eip1271.contract.Call(opts, &out, "isValidSignature", _data, _signature)
+	err := _Eip1271.contract.Call(opts, &out, "isValidSignature", _hash, _signature)
 
 	if err != nil {
 		return *new([4]byte), err
@@ -197,16 +197,16 @@ func (_Eip1271 *Eip1271Caller) IsValidSignature(opts *bind.CallOpts, _data []byt
 
 }
 
-// IsValidSignature is a free data retrieval call binding the contract method 0x20c13b0b.
+// IsValidSignature is a free data retrieval call binding the contract method 0x1626ba7e.
 //
-// Solidity: function isValidSignature(bytes _data, bytes _signature) view returns(bytes4 magicValue)
-func (_Eip1271 *Eip1271Session) IsValidSignature(_data []byte, _signature []byte) ([4]byte, error) {
-	return _Eip1271.Contract.IsValidSignature(&_Eip1271.CallOpts, _data, _signature)
+// Solidity: function isValidSignature(bytes32 _hash, bytes _signature) view returns(bytes4 magicValue)
+func (_Eip1271 *Eip1271Session) IsValidSignature(_hash [32]byte, _signature []byte) ([4]byte, error) {
+	return _Eip1271.Contract.IsValidSignature(&_Eip1271.CallOpts, _hash, _signature)
 }
 
-// IsValidSignature is a free data retrieval call binding the contract method 0x20c13b0b.
+// IsValidSignature is a free data retrieval call binding the contract method 0x1626ba7e.
 //
-// Solidity: function isValidSignature(bytes _data, bytes _signature) view returns(bytes4 magicValue)
-func (_Eip1271 *Eip1271CallerSession) IsValidSignature(_data []byte, _signature []byte) ([4]byte, error) {
-	return _Eip1271.Contract.IsValidSignature(&_Eip1271.CallOpts, _data, _signature)
+// Solidity: function isValidSignature(bytes32 _hash, bytes _signature) view returns(bytes4 magicValue)
+func (_Eip1271 *Eip1271CallerSession) IsValidSignature(_hash [32]byte, _signature []byte) ([4]byte, error) {
+	return _Eip1271.Contract.IsValidSignature(&_Eip1271.CallOpts, _hash, _signature)
 }
diff --git a/types_encoding.go b/types_encoding.go
index 9f1c59f..61c4b25 100644
--- a/types_encoding.go
+++ b/types_encoding.go
@@ -22,7 +22,6 @@ func (o *Operator) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (1) 'PubKey'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(o.PubKey)
 
 	// Field (1) 'PubKey'
 	if size := len(o.PubKey); size > 2048 {
@@ -53,7 +52,7 @@ func (o *Operator) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o1 < 12 {
+	if o1 != 12 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -136,7 +135,6 @@ func (i *Init) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (2) 'WithdrawalCredentials'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(i.WithdrawalCredentials)
 
 	// Field (3) 'Fork'
 	dst = append(dst, i.Fork[:]...)
@@ -194,7 +192,7 @@ func (i *Init) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 56 {
+	if o0 != 56 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -373,7 +371,6 @@ func (r *Reshare) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (6) 'WithdrawalCredentials'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(r.WithdrawalCredentials)
 
 	// Field (7) 'Owner'
 	dst = append(dst, r.Owner[:]...)
@@ -452,7 +449,7 @@ func (r *Reshare) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o1 < 116 {
+	if o1 != 116 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -670,10 +667,6 @@ func (r *ReshareMessage) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (1) 'Proofs'
 	dst = ssz.WriteOffset(dst, offset)
-	for ii := 0; ii < len(r.Proofs); ii++ {
-		offset += 4
-		offset += r.Proofs[ii].SizeSSZ()
-	}
 
 	// Field (0) 'Reshare'
 	if dst, err = r.Reshare.MarshalSSZTo(dst); err != nil {
@@ -717,7 +710,7 @@ func (r *ReshareMessage) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 8 {
+	if o0 != 8 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -838,7 +831,6 @@ func (s *SignedReshare) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (1) 'Signature'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(s.Signature)
 
 	// Field (0) 'Messages'
 	if size := len(s.Messages); size > 100 {
@@ -884,7 +876,7 @@ func (s *SignedReshare) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 8 {
+	if o0 != 8 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1013,7 +1005,6 @@ func (r *Resign) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (2) 'WithdrawalCredentials'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(r.WithdrawalCredentials)
 
 	// Field (3) 'Owner'
 	dst = append(dst, r.Owner[:]...)
@@ -1059,7 +1050,7 @@ func (r *Resign) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o2 < 92 {
+	if o2 != 92 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1171,10 +1162,6 @@ func (r *ResignMessage) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (2) 'Proofs'
 	dst = ssz.WriteOffset(dst, offset)
-	for ii := 0; ii < len(r.Proofs); ii++ {
-		offset += 4
-		offset += r.Proofs[ii].SizeSSZ()
-	}
 
 	// Field (0) 'Operators'
 	if size := len(r.Operators); size > 13 {
@@ -1236,7 +1223,7 @@ func (r *ResignMessage) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 12 {
+	if o0 != 12 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1406,7 +1393,6 @@ func (s *SignedResign) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (1) 'Signature'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(s.Signature)
 
 	// Field (0) 'Messages'
 	if size := len(s.Messages); size > 100 {
@@ -1452,7 +1438,7 @@ func (s *SignedResign) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 8 {
+	if o0 != 8 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1591,7 +1577,6 @@ func (r *Result) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (4) 'SignedProof'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += r.SignedProof.SizeSSZ()
 
 	// Field (4) 'SignedProof'
 	if dst, err = r.SignedProof.MarshalSSZTo(dst); err != nil {
@@ -1635,7 +1620,7 @@ func (r *Result) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o4 < 228 {
+	if o4 != 228 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1721,7 +1706,6 @@ func (p *Proof) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (1) 'EncryptedShare'
 	dst = ssz.WriteOffset(dst, offset)
-	offset += len(p.EncryptedShare)
 
 	// Field (2) 'SharePubKey'
 	if size := len(p.SharePubKey); size != 48 {
@@ -1765,7 +1749,7 @@ func (p *Proof) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o1 < 120 {
+	if o1 != 120 {
 		return ssz.ErrInvalidVariableOffset
 	}
 
@@ -1861,10 +1845,6 @@ func (s *SignedProof) MarshalSSZTo(buf []byte) (dst []byte, err error) {
 
 	// Offset (0) 'Proof'
 	dst = ssz.WriteOffset(dst, offset)
-	if s.Proof == nil {
-		s.Proof = new(Proof)
-	}
-	offset += s.Proof.SizeSSZ()
 
 	// Field (1) 'Signature'
 	if size := len(s.Signature); size != 256 {
@@ -1897,7 +1877,7 @@ func (s *SignedProof) UnmarshalSSZ(buf []byte) error {
 		return ssz.ErrOffset
 	}
 
-	if o0 < 260 {
+	if o0 != 260 {
 		return ssz.ErrInvalidVariableOffset
 	}