diff --git a/proxy/shadowsocks/protocol.go b/proxy/shadowsocks/protocol.go
index e3f582dfa..b8764d451 100644
--- a/proxy/shadowsocks/protocol.go
+++ b/proxy/shadowsocks/protocol.go
@@ -8,7 +8,6 @@ import (
 	"v2ray.com/core/common"
 	"v2ray.com/core/common/bitmask"
 	"v2ray.com/core/common/buf"
-	"v2ray.com/core/common/dice"
 	"v2ray.com/core/common/net"
 	"v2ray.com/core/common/protocol"
 )
@@ -65,12 +64,7 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 	buffer.Clear()
 
 	addr, port, err := addrParser.ReadAddressPort(buffer, br)
-
 	if err != nil {
-		// Invalid address. Continue to read some bytes to confuse client.
-		nBytes := dice.Roll(32) + 1
-		buffer.Clear()
-		buffer.AppendSupplier(buf.ReadFullFrom(br, int32(nBytes)))
 		return nil, nil, newError("failed to read address").Base(err)
 	}
 
diff --git a/proxy/vmess/encoding/server.go b/proxy/vmess/encoding/server.go
index 4c5c76dc9..a035a693a 100644
--- a/proxy/vmess/encoding/server.go
+++ b/proxy/vmess/encoding/server.go
@@ -15,7 +15,6 @@ import (
 	"v2ray.com/core/common/bitmask"
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/crypto"
-	"v2ray.com/core/common/dice"
 	"v2ray.com/core/common/net"
 	"v2ray.com/core/common/protocol"
 	"v2ray.com/core/common/serial"
@@ -175,20 +174,6 @@ func (s *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.Request
 	// 1 bytes reserved
 	request.Command = protocol.RequestCommand(buffer.Byte(37))
 
-	var invalidRequestErr error
-	defer func() {
-		if invalidRequestErr != nil {
-			randomLen := dice.Roll(64) + 1
-			// Read random number of bytes for prevent detection.
-			buffer.AppendSupplier(buf.ReadFullFrom(decryptor, int32(randomLen))) // nolint: errcheck
-		}
-	}()
-
-	if request.Security == protocol.SecurityType_UNKNOWN || request.Security == protocol.SecurityType_AUTO {
-		invalidRequestErr = newError("unknown security type")
-		return nil, invalidRequestErr
-	}
-
 	switch request.Command {
 	case protocol.RequestCommandMux:
 		request.Address = net.DomainAddress("v1.mux.cool")
@@ -197,13 +182,7 @@ func (s *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.Request
 		if addr, port, err := addrParser.ReadAddressPort(buffer, decryptor); err == nil {
 			request.Address = addr
 			request.Port = port
-		} else {
-			invalidRequestErr = newError("invalid address").Base(err)
-			return nil, invalidRequestErr
 		}
-	default:
-		invalidRequestErr = newError("invalid request command: ", request.Command)
-		return nil, invalidRequestErr
 	}
 
 	if padingLen > 0 {
@@ -229,6 +208,10 @@ func (s *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.Request
 		return nil, newError("invalid remote address")
 	}
 
+	if request.Security == protocol.SecurityType_UNKNOWN || request.Security == protocol.SecurityType_AUTO {
+		return nil, newError("unknown security type: ", request.Security)
+	}
+
 	return request, nil
 }