HTML5 Client Side Data Encryption - What are my options?

Question

I am working on a EDIT: mobile web app which displays some sensitive information and requires a login which stores the members username and password in a HT

Answer 1

David Dahl, a Firefox engineer, has a prototype Firefox extension, domcrypt (repository on github), that provides Javascript access to Firefox's NSS (Network Security Services) APIs. Since Chrome also uses NSS, providing the same API is probably straightforward for it as well.

He's pushing Mozilla to evolve it a bit more for eventual inclusion within Firefox; we'll see what happens.