one
Systems and methods of key selection for cryptographic authentication of contactless cards

Abstract:

Example embodiments of systems and methods for data transmission between a contactless card and a server are provided. The card may include an applet, a counter, and a plurality of encryption keys. The applet may rotate the plurality of keys based on a predetermined key rotation, select one or more keys for a cryptographic operation, perform the operation using the selected keys and the counter to generate a cryptographic result, and transmit the result and the counter to the server. Upon receipt of the result, a server, in communication with the card and containing the plurality of encryption keys, may rotate the plurality of keys based on the predetermined key rotation, select one or more keys for decryption, wherein the keys selected by the server matches the keys selected by the applet, and perform the decryption on the result.