I've read elsewhere (http://forums.udacity.com/questions/6028436/bcrypt-not-suitable-for-pythongae) that bcrypt is not suitable for use on Google App Engine. What are some good ways to create a user signup/login system (with usernames/emails & passwords) without rolling your own when using Google App Engine for Python? Thanks!
The PBKDF2 algorithm available from the passlib library will do the trick.
It doesn't have some appealing properties of bcrypt such as being hard to speedup using GPUs but it is still a strong password hashing with a configurable iteration count.