Here's one for TextSecure: https://eprint.iacr.org/2014/904.pdf https://eprint.iacr.org/2014/904.pdf They claim doing the equivalent for WhatsApp is future work

Here's one for TextSecure: https://eprint.iacr.org/2014/904.pdf https://eprint.iacr.org/2014/904.pdf They claim doing the equivalent for WhatsApp is future work, although the paper is a year or two old.