diff --git a/TransitTunnel.cpp b/TransitTunnel.cpp
index aa4636d6..6fc6c5c0 100644
--- a/TransitTunnel.cpp
+++ b/TransitTunnel.cpp
@@ -22,7 +22,7 @@ namespace tunnel
 
 	void TransitTunnel::EncryptTunnelMsg (std::shared_ptr<I2NPMessage> tunnelMsg)
 	{		
-		m_Encryption.Encrypt (tunnelMsg->GetPayload () + 4); 
+		m_Encryption.Encrypt (tunnelMsg->GetPayload () + 4, tunnelMsg->GetPayload () + 4); 
 	}	
 
 	TransitTunnelParticipant::~TransitTunnelParticipant ()
diff --git a/Tunnel.cpp b/Tunnel.cpp
index 5341da32..de95ad68 100644
--- a/Tunnel.cpp
+++ b/Tunnel.cpp
@@ -146,7 +146,7 @@ namespace tunnel
 		TunnelHopConfig * hop = m_Config->GetLastHop (); 
 		while (hop)
 		{	
-			hop->decryption.Decrypt (payload);
+			hop->decryption.Decrypt (payload, payload);
 			hop = hop->prev;
 		}
 	}	
diff --git a/aes.cpp b/aes.cpp
index 8d270521..506e7ca8 100644
--- a/aes.cpp
+++ b/aes.cpp
@@ -280,74 +280,76 @@ namespace crypto
 #endif
 	}
 
-	void TunnelEncryption::Encrypt (uint8_t * payload)
+	void TunnelEncryption::Encrypt (const uint8_t * in, uint8_t * out)
 	{
 #ifdef AESNI
 		__asm__
 		(
             // encrypt IV 
-			"movups	(%[payload]), %%xmm0 \n"
+			"movups	(%[in]), %%xmm0 \n"
 			EncryptAES256(sched_iv)
 			"movaps %%xmm0, %%xmm1 \n"
 			// double IV encryption
 			EncryptAES256(sched_iv)
-			"movups %%xmm0, (%[payload]) \n"
+			"movups %%xmm0, (%[out]) \n"
 			// encrypt data, IV is xmm1
 			"1: \n"
-			"add $16, %[payload] \n"
-		 	"movups	(%[payload]), %%xmm0 \n"
+			"add $16, %[in] \n"
+		    "add $16, %[out] \n"
+		 	"movups	(%[in]), %%xmm0 \n"
 		 	"pxor %%xmm1, %%xmm0 \n"
 		 	EncryptAES256(sched_l)
 		 	"movaps	%%xmm0, %%xmm1 \n"	
-		 	"movups	%%xmm0, (%[payload]) \n"
+		 	"movups	%%xmm0, (%[out]) \n"
 		 	"dec %[num] \n"
 		 	"jnz 1b \n"	 	
 			: 
 			: [sched_iv]"r"(m_IVEncryption.GetKeySchedule ()), [sched_l]"r"(m_LayerEncryption.GetKeySchedule ()), 
-			  [payload]"r"(payload), [num]"r"(63) // 63 blocks = 1008 bytes
+			  [in]"r"(in), [out]"r"(out), [num]"r"(63) // 63 blocks = 1008 bytes
 			: "%xmm0", "%xmm1", "cc", "memory"
 		);
 #else
-		m_IVEncryption.Encrypt ((ChipherBlock *)payload, (ChipherBlock *)payload); // iv
-		m_LayerEncryption.SetIV (payload);
-		m_LayerEncryption.Encrypt (payload + 16, i2p::tunnel::TUNNEL_DATA_ENCRYPTED_SIZE, payload + 16); // data
-		m_IVEncryption.Encrypt ((ChipherBlock *)payload, (ChipherBlock *)payload); // double iv
+		m_IVEncryption.Encrypt ((const ChipherBlock *)in, (ChipherBlock *)out); // iv
+		m_LayerEncryption.SetIV (out);
+		m_LayerEncryption.Encrypt (in + 16, i2p::tunnel::TUNNEL_DATA_ENCRYPTED_SIZE, out + 16); // data
+		m_IVEncryption.Encrypt ((ChipherBlock *)out, (ChipherBlock *)out); // double iv
 #endif
 	}
 
-	void TunnelDecryption::Decrypt (uint8_t * payload)
+	void TunnelDecryption::Decrypt (const uint8_t * in, uint8_t * out)
 	{
 #ifdef AESNI
 		__asm__
 		(
             // decrypt IV 
-			"movups	(%[payload]), %%xmm0 \n"
+			"movups	(%[in]), %%xmm0 \n"
 			DecryptAES256(sched_iv)
 			"movaps %%xmm0, %%xmm1 \n"
 			// double IV encryption
 			DecryptAES256(sched_iv)
-			"movups %%xmm0, (%[payload]) \n"
+			"movups %%xmm0, (%[out]) \n"
 			// decrypt data, IV is xmm1
 			"1: \n"
-			"add $16, %[payload] \n"
-			"movups	(%[payload]), %%xmm0 \n"
+			"add $16, %[in] \n"
+		    "add $16, %[out] \n"
+			"movups	(%[in]), %%xmm0 \n"
 			"movaps %%xmm0, %%xmm2 \n"
 		 	DecryptAES256(sched_l)
 			"pxor %%xmm1, %%xmm0 \n"
-		 	"movups	%%xmm0, (%[payload]) \n"
+		 	"movups	%%xmm0, (%[out]) \n"
 			"movaps %%xmm2, %%xmm1 \n"
 		 	"dec %[num] \n"
 		 	"jnz 1b \n"	 	
 			: 
 			: [sched_iv]"r"(m_IVDecryption.GetKeySchedule ()), [sched_l]"r"(m_LayerDecryption.GetKeySchedule ()), 
-			  [payload]"r"(payload), [num]"r"(63) // 63 blocks = 1008 bytes
+			  [in]"r"(in), [out]"r"(out), [num]"r"(63) // 63 blocks = 1008 bytes
 			: "%xmm0", "%xmm1", "%xmm2", "cc", "memory"
 		);
 #else
-		m_IVDecryption.Decrypt ((ChipherBlock *)payload, (ChipherBlock *)payload); // iv
-		m_LayerDecryption.SetIV (payload);	
-		m_LayerDecryption.Decrypt (payload + 16, i2p::tunnel::TUNNEL_DATA_ENCRYPTED_SIZE, payload + 16); // data
-		m_IVDecryption.Decrypt ((ChipherBlock *)payload, (ChipherBlock *)payload); // double iv
+		m_IVDecryption.Decrypt ((const ChipherBlock *)in, (ChipherBlock *)out); // iv
+		m_LayerDecryption.SetIV (out);	
+		m_LayerDecryption.Decrypt (in + 16, i2p::tunnel::TUNNEL_DATA_ENCRYPTED_SIZE, out + 16); // data
+		m_IVDecryption.Decrypt ((ChipherBlock *)out, (ChipherBlock *)out); // double iv
 #endif
 	}
 }
diff --git a/aes.h b/aes.h
index 95180fd6..84ca1f17 100644
--- a/aes.h
+++ b/aes.h
@@ -185,7 +185,7 @@ namespace crypto
 				m_IVEncryption.SetKey (ivKey);
 			}	
 
-			void Encrypt (uint8_t * payload); // 1024 bytes (16 IV + 1008 data)		
+			void Encrypt (const uint8_t * in, uint8_t * out); // 1024 bytes (16 IV + 1008 data)		
 
 		private:
 
@@ -207,7 +207,7 @@ namespace crypto
 				m_IVDecryption.SetKey (ivKey);
 			}			
 
-			void Decrypt (uint8_t * payload); // 1024 bytes (16 IV + 1008 data)	
+			void Decrypt (const uint8_t * in, uint8_t * out); // 1024 bytes (16 IV + 1008 data)	
 
 		private: