> I do expect users to hash the message before passing it to ECDSA, this way you could use any hashing library with it. Though, elliptic.js does actually depends on hash.js to seed it's PRNG.

I think this isn't a good design because most people won't know that they must hash the message before passing it to the ECDSA. People will misuse it, and open themselves to attacks.

What you can do instead is to pick the right hash based on the curve, like what we did in End-To-End: https://code.google.com/p/end-to-end/source/browse/javascrip....