Automatic password rollover

A method comprising:

• receiving, by a microprocessor, a first device nonce and a first Hash based Message Authentication Code (HMAC) of the first device nonce using an old password as a key;
• comparing, by the microprocessor, the received first HMAC to a computed second HMAC of the received first device nonce using a stored old password as the key for a match;
• in response to the match, computing, by the microprocessor, a third HMAC of a second device nonce using the stored old password as the key;
• sending, by the microprocessor, a change password acknowledgement message that comprises the second device nonce and the third HMAC;
• computing, by the microprocessor, a final secret using a second device secret and the first device nonce;
• and
• computing, by the microprocessor, a new password using a key derivation function that uses the old password and the final secret.

A system comprising:

• a microprocessor;
• and
• a computer readable medium, coupled with the microprocessor and comprising microprocessor readable and executable instructions that, when executed by the microprocessor, cause the microprocessor to:
• compute a first Hash based Message Authentication Code (HMAC) using a first device nonce with a stored old password as a key;
• send, from a first device, to a second device, the first device nonce and the first HMAC of the first device nonce with the stored old password as the key;
• receive a change password acknowledgment message from the second device that comprises a second device nonce and a second HMAC of a second device nonce using an old password as the key;
• compute a final secret using a first device secret and the second device nonce;
• and
• compute a new password using a key derivation function that uses the old password and the final secret.