Methods, systems, and devices are disclosed for using a payment processing network as an authorization engine to access secure physical areas, such as college dormitories, office buildings. A keycard with a cryptogram generator is presented by a user to an access device, and the access device or associated computer sends an access request message formatted like a payment authentication request message to an aggregator/acquirer and payment processing network. The payment processing network validates the cryptogram and returns an access response message, again formatted like a payment authorization response message, indicating that the keycard is authentic. The gate, door, turnstile, or other barrier is then temporarily unlocked to let the user through.