Telefonica and Turkcell are both deploying a fascinating new service, Mobile Signature, which uses a cryptographic ID stored on the SIM card to offer two-factor authentication for the Web. Basically, you provide a user number when you need to prove your identity to a third party; they call the telco’s ID API, which sends a WAP PUSH message to your phone. It knows it’s your phone because it authenticates against the crypto key on the SIM card. You verify the challenge, and you’re done as they say at Amazon.

Vía Telco 2.0.