Hi, I'm searching information about the way you implement tls v1.1 for cbc mode I've read the rfc4346 It mention that it use explicit IV I've read the openssl code in openssl 1.0.1. And I don't know how it was implemented. I think at the beginning of the message you add (mask || R) but after I dont understand if the chaining method it the same as tls1.0 => E(key,residu || data ) Can you explain me a bit the process because I'm lost and I didn't find any internet information about implementation. Best Regards Fred