3.0.0
As of 3.0.0, python-jose uses the pure python rsa package for signing and verifying RSA signatures by default.
Other backends can be used by installing python-jose with extras. Options include pycrypto, pycryptodome and cryptography. It is recommended that one of these options is used in production, as they will be much faster than the pure python rsa module.
The cryptography option is a good default.