diff --git a/device/device.go b/device/device.go
index 18376ee..d9497a1 100644
--- a/device/device.go
+++ b/device/device.go
@@ -630,7 +630,7 @@ func (device *Device) handlePostConfig(tempASecCfg *aSecCfgType) (err error) {
 		}
 	}
 	if tempASecCfg.initPacketJunkSize != 0 {
-		if 148+tempASecCfg.initPacketJunkSize >= MaxSegmentSize {
+		if MessageInitiationSize+tempASecCfg.initPacketJunkSize >= MaxSegmentSize {
 			if err != nil {
 				err = ipcErrorf(
 					ipc.IpcErrorInvalid,
@@ -656,7 +656,7 @@ func (device *Device) handlePostConfig(tempASecCfg *aSecCfgType) (err error) {
 		}
 	}
 	if tempASecCfg.responsePacketJunkSize != 0 {
-		if 92+tempASecCfg.responsePacketJunkSize >= MaxSegmentSize {
+		if MessageResponseSize+tempASecCfg.responsePacketJunkSize >= MaxSegmentSize {
 			if err != nil {
 				err = ipcErrorf(
 					ipc.IpcErrorInvalid,
@@ -720,19 +720,42 @@ func (device *Device) handlePostConfig(tempASecCfg *aSecCfgType) (err error) {
 		MessageTransportType = 4
 	}
 
-	packetSizeToMsgType = map[int]uint32{
-		MessageInitiationSize + device.aSecCfg.initPacketJunkSize:   MessageInitiationType,
-		MessageResponseSize + device.aSecCfg.responsePacketJunkSize: MessageResponseType,
-		MessageCookieReplySize: MessageCookieReplyType,
-		MessageTransportSize:   MessageTransportType,
+	newInitSize := MessageInitiationSize + device.aSecCfg.initPacketJunkSize
+	newResponseSize := MessageResponseSize + device.aSecCfg.responsePacketJunkSize
+
+	if newInitSize == newResponseSize {
+		if err != nil {
+			err = ipcErrorf(
+				ipc.IpcErrorInvalid,
+				`new init size:%d; and new response size:%d; should differ; %w`,
+				newInitSize,
+				newResponseSize,
+				err,
+			)
+		} else {
+			err = ipcErrorf(
+				ipc.IpcErrorInvalid,
+				`new init size:%d; and new response size:%d; should differ`,
+				newInitSize,
+				newResponseSize,
+			)
+		}
+	} else {		
+		packetSizeToMsgType = map[int]uint32{
+			newInitSize:   MessageInitiationType,
+			newResponseSize: MessageResponseType,
+			MessageCookieReplySize: MessageCookieReplyType,
+			MessageTransportSize:   MessageTransportType,
+		}
+	
+		msgTypeToJunkSize = map[uint32]int{
+			MessageInitiationType:  device.aSecCfg.initPacketJunkSize,
+			MessageResponseType:    device.aSecCfg.responsePacketJunkSize,
+			MessageCookieReplyType: 0,
+			MessageTransportType:   0,
+		}
 	}
 
-	msgTypeToJunkSize = map[uint32]int{
-		MessageInitiationType:  device.aSecCfg.initPacketJunkSize,
-		MessageResponseType:    device.aSecCfg.responsePacketJunkSize,
-		MessageCookieReplyType: 0,
-		MessageTransportType:   0,
-	}
 	device.isASecOn.SetTo(isASecOn)
 	device.aSecMux.Unlock()
 	
diff --git a/device/receive.go b/device/receive.go
index df9671e..cc031b2 100644
--- a/device/receive.go
+++ b/device/receive.go
@@ -135,15 +135,24 @@ func (device *Device) RoutineReceiveIncoming(
 			// check size of packet
 
 			packet := bufsArrs[i][:size]
+			var msgType uint32
 			if device.isAdvancedSecurityOn() {
 				var junkSize int
-				if msgType, ok := packetSizeToMsgType[size]; ok {
-					junkSize = msgTypeToJunkSize[msgType]
+				if mapMsgType, ok := packetSizeToMsgType[size]; ok {
+					junkSize = msgTypeToJunkSize[mapMsgType]
+					msgType = mapMsgType
+				} else {
+					msgType = binary.LittleEndian.Uint32(packet[:4])
+					if msgType != MessageTransportType {
+						device.log.Verbosef("ASec: Received message with unknown type")
+						continue
+					} 
 				}
 				// shift junk
 				packet = packet[junkSize:]
+			} else {
+				msgType = binary.LittleEndian.Uint32(packet[:4])
 			}
-			msgType := binary.LittleEndian.Uint32(packet[:4])
 			switch msgType {
 
 			// check if transport