Recommendation for Javascript RSA Libs??

Anyone using or know of a pure JS RSA lib? My use case would be to encrypt/decrypt messages and use ACS to send and receive. Messages would only be viewable between the sending and receiving device.

For Example:

var encryptedMessage = rsalib.encrypt('plaintext message', public_key);
 
Cloud.Messages.create({
    to_ids: 'some_user',
    body: encryptedMessage,
    subject: 'Test Message'
},

During the user registration process (in the mobile app) create the keys and store the public in the user object on ACS and the private on the mobile device.

Cloud.Users.create({
...,
pubilc_key: 'yada-yada'
})

Here is one option i've ran across. I've google, but most of the projects look outdated.

http://www-cs-students.stanford.edu/~tjw/jsbn/

Looks like the Wc3 is still figuring things out: http://www.w3.org/TR/WebCryptoAPI/