METHODS FOR SECURE CRYPTOGRAM GENERATION

摘要

Embodiments of the invention introduce efficient methods for securely generating a cryptogram by a user device, and validating the cryptogram by a server computer. In some embodiments, a secure communication can be conducted whereby a user device provides a cryptogram without requiring the user device to persistently store an encryption key or other sensitive data used to generate the cryptogram. For example, the user device and server computer can mutually authenticate and establish a shared secret. Using the shared secret, the server computer can derive a session key and transmit key derivation parameters encrypted using the session key to the user device. The user device can also derive the session key using the shared secret, decrypt the encrypted key derivation parameters, and store the key derivation parameters. Key derivation parameters and the shared secret can be used to generate a single use cryptogram key. The cryptogram key can be used to generate a cryptogram for conducting secure communications.

主权项

1. A computer-implemented method comprising:
determining, by a user device, an ephemeral key pair comprising an ephemeral public key and an ephemeral private key; sending, by the user device, a provisioning request message including the ephemeral public key to a provisioning server computer; receiving, by the user device, a provisioning response message including encrypted credentials from the provisioning server computer; determining, by the user device, a response shared secret using the ephemeral private key and a static server public key; decrypting, by the user device, the encrypted credentials using the response shared secret to determine credentials; obtaining key derivation parameters from the credentials; and deriving a first cryptogram key from the response shared secret using the key derivation parameters, the first cryptogram key operable to generate a first cryptogram for use in a first secure communication with a validation server computer.