diff --git a/fhevm/contracts_test.go b/fhevm/contracts_test.go
index fa0e20f..1d61c64 100644
--- a/fhevm/contracts_test.go
+++ b/fhevm/contracts_test.go
@@ -1,19 +1,3 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
 package fhevm
 
 import (
diff --git a/fhevm/instructions.go b/fhevm/instructions.go
index f2a08a1..b655207 100644
--- a/fhevm/instructions.go
+++ b/fhevm/instructions.go
@@ -184,6 +184,7 @@ func verifyIfCiphertextHandle(handle common.Hash, env EVMEnvironment, contractAd
 	return nil
 }
 
+// This function is a modified copy from https://github.com/ethereum/go-ethereum
 func OpSload(pc *uint64, env EVMEnvironment, scope ScopeContext) ([]byte, error) {
 	loc := scope.GetStack().Peek()
 	hash := common.Hash(loc.Bytes32())
@@ -265,6 +266,7 @@ func persistIfVerifiedCiphertext(flagHandleLocation common.Hash, handle common.H
 }
 
 func OpSstore(pc *uint64, env EVMEnvironment, scope ScopeContext) ([]byte, error) {
+	// This function is a modified copy from https://github.com/ethereum/go-ethereum
 	if env.IsReadOnly() {
 		return nil, ErrWriteProtection
 	}
@@ -348,6 +350,7 @@ func RemoveVerifiedCipherextsAtCurrentDepth(env EVMEnvironment) {
 }
 
 func OpReturn(pc *uint64, env EVMEnvironment, scope ScopeContext) []byte {
+	// This function is a modified copy from https://github.com/ethereum/go-ethereum
 	offset, size := scope.GetStack().Pop(), scope.GetStack().Pop()
 	ret := scope.GetMemory().GetPtr(int64(offset.Uint64()), int64(size.Uint64()))
 	delegateCiphertextHandlesToCaller(env, ret)
@@ -355,6 +358,7 @@ func OpReturn(pc *uint64, env EVMEnvironment, scope ScopeContext) []byte {
 }
 
 func OpSelfdestruct(pc *uint64, env EVMEnvironment, scope ScopeContext) (beneficiary uint256.Int, balance *big.Int) {
+	// This function is a modified copy from https://github.com/ethereum/go-ethereum
 	beneficiary = scope.GetStack().Pop()
 	protectedStorage := fhevm_crypto.CreateProtectedStorageContractAddress(scope.GetContract().Address())
 	balance = env.GetBalance(scope.GetContract().Address())
diff --git a/fhevm/instructions_test.go b/fhevm/instructions_test.go
index 8f8ad7c..aeff3ff 100644
--- a/fhevm/instructions_test.go
+++ b/fhevm/instructions_test.go
@@ -1,19 +1,3 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
 package fhevm
 
 import (
diff --git a/fhevm/memory.go b/fhevm/memory.go
index a263e78..3eb205b 100644
--- a/fhevm/memory.go
+++ b/fhevm/memory.go
@@ -1,24 +1,3 @@
-// BSD 3-Clause Clear License
-
-// Copyright © 2023 ZAMA.
-// All rights reserved.
-
-// Copyright 2015 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
 package fhevm
 
 import "github.com/holiman/uint256"
diff --git a/fhevm/params.go b/fhevm/params.go
index af9bdc5..577d205 100644
--- a/fhevm/params.go
+++ b/fhevm/params.go
@@ -1,23 +1,3 @@
-// BSD 3-Clause Clear License
-
-// Copyright © 2023 ZAMA.
-// All rights reserved.
-
-// Copyright 2015 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 package fhevm
 
 // This file contains default gas costs of fhEVM-related operations.
diff --git a/fhevm/tfhe_test.go b/fhevm/tfhe_test.go
index 96e7911..8c6b715 100644
--- a/fhevm/tfhe_test.go
+++ b/fhevm/tfhe_test.go
@@ -1,19 +1,3 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
 package fhevm
 
 import (
diff --git a/fhevm/tfhe_wrappers.go b/fhevm/tfhe_wrappers.go
index 2633684..d14adf8 100644
--- a/fhevm/tfhe_wrappers.go
+++ b/fhevm/tfhe_wrappers.go
@@ -1,19 +1,3 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
 package fhevm
 
 /*