Cryptographic authentication techniques for mobile devices

A method of authenticating a computing device to a back-end subsystem. In one embodiment a prover black-box in the computing device regenerates a credential containing a key pair from a PIN and a protocredential, and authenticates cryptographically to a verifier black-box in the back-end subsystem; then the verifier black-box sends an authentication token to the prover black-box as verifiable confirmation of the cryptographic authentication, the prover black-box sends the authentication token to an application front-end in the computing device, the application front-end sends the authentication token to an application back-end in the back-end subsystem, and the application back-end verifies the authentication token.