Everytime a new versions of browsers show up I hear about new stuff being added, like say webGL and other technologies that no one really knows if they catch up.
For anybody still looking for this information. There is a WebCrypto API which appears to have been finalised at the beginning of 2017.
To use it in a browser, you can find it at window.crypto.subtle which contains methods for encryption, digests etc. Documentation on the available functions here.