diff --git a/server/wsproxy/kcpsession.cc b/server/wsproxy/kcpsession.cc
index 50126ba..fc41b91 100644
--- a/server/wsproxy/kcpsession.cc
+++ b/server/wsproxy/kcpsession.cc
@@ -85,10 +85,10 @@ void KcpSession::DecodeUserPacket(char* buf, int& offset, unsigned int buflen)
     //packagelen + msgid + magiccode + msgbody
     //2 + 2 + 4+ xx + \0 + xx
     bool warning = false;
-    while (buflen - offset >= sizeof(f8::PackHead)) {
-        f8::PackHead* p = (f8::PackHead*)&buf[offset];
+    while (buflen - offset >= sizeof(f8::PackHead) + GetSecretKeyLen()) {
+        f8::PackHead* p = (f8::PackHead*)&buf[offset + GetSecretKeyLen()];
         if (p->magic_code == f8::MAGIC_CODE) {
-            if (buflen - offset < sizeof(f8::PackHead) + p->packlen) {
+            if (buflen - offset < sizeof(f8::PackHead) + p->packlen + GetSecretKeyLen()) {
                 break;
             }
             //a8::XPrintf("Recv MsgId:%d\n", {p->msgid});
@@ -98,7 +98,7 @@ void KcpSession::DecodeUserPacket(char* buf, int& offset, unsigned int buflen)
                                           //saddr,
                                           p->msgid,
                                           p->seqid,
-                                          &buf[offset + sizeof(f8::PackHead)],
+                                          &buf[offset + sizeof(f8::PackHead) + GetSecretKeyLen()],
                                           p->packlen);
             offset += sizeof(f8::PackHead) + p->packlen;
         } else {
diff --git a/server/wsproxy/kcpsession.h b/server/wsproxy/kcpsession.h
index 6f72d3e..c1ee0e9 100644
--- a/server/wsproxy/kcpsession.h
+++ b/server/wsproxy/kcpsession.h
@@ -22,6 +22,12 @@ public:
     void SendClientMsg(char* buf, int buf_len);
     virtual void OnRecvPacket(a8::UdpPacket* pkt) override;
 
+    static int GetSecretKeyLen() { return sizeof(long long) / 4; }
+    static long long ReadSecretKey(const char* buf, int buf_len)
+    {
+        return buf_len < GetSecretKeyLen() ? 0 : *((long long*)buf);
+    }
+
 protected:
     virtual void DecodeUserPacket(char* buf, int& offset, unsigned int buflen) override;
 
diff --git a/server/wsproxy/longsessionmgr.cc b/server/wsproxy/longsessionmgr.cc
index d0779a5..0a1bbda 100644
--- a/server/wsproxy/longsessionmgr.cc
+++ b/server/wsproxy/longsessionmgr.cc
@@ -81,11 +81,14 @@ std::shared_ptr<LongSession> LongSessionMgr::GetSession(int socket_handle)
 
 void LongSessionMgr::ProcUdpPacket(a8::UdpPacket* pkt)
 {
-    int socket_handle = 0;
-    long long secret_key = 0;
-    auto session = GetSession(socket_handle);
-    if (session && secret_key == session->GetKcpSession()->GetSecretKey()) {
-        session->GetKcpSession()->OnRecvPacket(pkt);
+    const int IKCP_OVERHEAD = 24;
+    if (pkt->buf_len > IKCP_OVERHEAD + KcpSession::GetSecretKeyLen()) {
+        int socket_handle = ikcp_getconv(pkt->buf);
+        long long secret_key = KcpSession::ReadSecretKey(pkt->buf, pkt->buf_len);
+        auto session = GetSession(socket_handle);
+        if (session && secret_key == session->GetKcpSession()->GetSecretKey()) {
+            session->GetKcpSession()->OnRecvPacket(pkt);
+        }
     }
 }