Global Platform : differences between Secure Channel Protocol(s) 1 and 2
843851Jun 19 2006 — edited Jun 23 2006Hi,
I have some questions about the Secure Channel Protocols described by GlobalPlatform.
The response APDU to the INITIALIZE UPDATE command differs in SCP1 and SCP2 :
SCP1 : the cardChallenge sizes 8 bytes
SCP2 : the cardChallenge sizes 6 bytes (+a 2 bytes sequence counter)
Since the cardChallenge (and the hostChallenge) are used to create the d�rivation data (16 bytes), in SCP1, how the the derivation data is created in SCP 2 ?
What is the purpose of the key diversification data (first 10 bytes of the initialize update command response) ? How am I supposed to use it to change the static keys ?
In SCP2, the EXTERNAL AUTHENTICATE command has to send the host cryptogram (8 bytes) and a MAC (8 bytes). How is this MAC built by the host application ?