diff --git a/command/open_session.cpp b/command/open_session.cpp
index d29cbf1..f33de3c 100644
--- a/command/open_session.cpp
+++ b/command/open_session.cpp
@@ -19,8 +19,8 @@
     auto response = reinterpret_cast<OpenSessionResponse*>(outPayload.data());
 
     // Check for valid Authentication Algorithms
-    if (request->authAlgo != static_cast<uint8_t>
-        (cipher::rakp_auth::Algorithms::RAKP_HMAC_SHA1))
+    if (!cipher::rakp_auth::Interface::isAlgorithmSupported(
+                static_cast<cipher::rakp_auth::Algorithms>(request->authAlgo)))
     {
         response->status_code =
             static_cast<uint8_t>(RAKP_ReturnCode::INVALID_AUTH_ALGO);
@@ -28,8 +28,8 @@
     }
 
     // Check for valid Integrity Algorithms
-    if(!cipher::integrity::Interface::isAlgorithmSupported(static_cast
-                    <cipher::integrity::Algorithms>(request->intAlgo)))
+    if (!cipher::integrity::Interface::isAlgorithmSupported(
+                static_cast<cipher::integrity::Algorithms>(request->intAlgo)))
     {
         response->status_code =
             static_cast<uint8_t>(RAKP_ReturnCode::INVALID_INTEGRITY_ALGO);
diff --git a/command/rakp34.cpp b/command/rakp34.cpp
index 8c95e95..5ba9aa1 100644
--- a/command/rakp34.cpp
+++ b/command/rakp34.cpp
@@ -8,6 +8,7 @@
 #include "endian.hpp"
 #include "guid.hpp"
 #include "main.hpp"
+#include "rmcp.hpp"
 
 namespace command
 {
@@ -44,8 +45,11 @@
     {
         case cipher::crypt::Algorithms::AES_CBC_128:
         {
-            session->setCryptAlgo(std::make_unique<cipher::crypt::AlgoAES128>(
-                                 authAlgo->sessionIntegrityKey));
+            auto intAlgo = session->getIntegrityAlgo();
+            auto k2 = intAlgo->generateKn(
+                    authAlgo->sessionIntegrityKey, rmcp::const_2);
+            session->setCryptAlgo(
+                    std::make_unique<cipher::crypt::AlgoAES128>(k2));
             break;
         }
         default:
@@ -63,7 +67,7 @@
     auto response = reinterpret_cast<RAKP4response*>(outPayload.data());
 
     // Check if the RAKP3 Payload Length is as expected
-    if(inPayload.size() != sizeof(RAKP3request))
+    if (inPayload.size() < sizeof(RAKP3request))
     {
         std::cerr << "RAKP34: Invalid RAKP3 request\n";
         response->rmcpStatusCode =
@@ -145,8 +149,8 @@
     // Generate Key Exchange Authentication Code - RAKP2
     auto output = authAlgo->generateHMAC(input);
 
-    if (std::memcmp(output.data(), request->keyExchangeAuthCode,
-                    output.size()))
+    if (inPayload.size() != (sizeof(RAKP3request) + output.size()) ||
+            std::memcmp(output.data(), request+1, output.size()))
     {
         std::cerr << "Mismatch in HMAC sent by remote console\n";
 
diff --git a/command/rakp34.hpp b/command/rakp34.hpp
index deaf2e9..2f00823 100644
--- a/command/rakp34.hpp
+++ b/command/rakp34.hpp
@@ -19,7 +19,6 @@
     uint8_t rmcpStatusCode;
     uint16_t reserved;
     uint32_t managedSystemSessionID;
-    uint8_t keyExchangeAuthCode[20];
 } __attribute__((packed));
 
 /**