There is no difference, WhatsApp and Signal both use the Signal Protocol, and the same code: https://github.com/whispersystems/libsignal-protocol-java
Re:WhatsApp Security Whitepaper [pdf]
by CiPHPerCoder on Tuesday April 05, 2016 @04:27PM
(#11434079)
Oh, excellent.
(Last I checked it was still AES-128 and SHA-1, but that was before the name change and I wasn't sure if it had changed. Glad to hear it has.)
- WhatsApp uses AES-256 instead of AES-128 (both are CBC mode)
- WhatsApp uses HMAC-SHA-256 instead of HMAC-SHA-1
I think everything else is the same. (I need to re-read the Signal Protocol specification later today to make sure.)