Messages after Handshake

Hello makers!
I currently implementing my own private cloud. Therefore i created a Handshake that is very close to the ‘spark-protocol’ github repo served by you. I can successful do the handshake and receiving some packets. But after 15seconds when the first Ping-Messages kicks in from the core. My encryption fails. Here is my repo:

Any Ideas? It driving me crazy because the changing IV of the aes-128-cbc seems to work…

iam using
node -v

Here is a sample log of my local cloud:

Any particular reason for not using the local cloud server from Particle?