Secure real-time clock update in an access control system

An access control device, comprising:

• a processor;
• and
• a memory comprising a plurality of instructions stored thereon that, in response to execution by the processor, causes the access control device to:
• transmit a wireless communication message that identifies a clock status of a real-time clock of the access control device to a computing device, wherein the clock status includes a clock status value indicating that the real-time clock has not been set after a reset event;
• transmit a session random value to the computing device;
• receive a clock update token from the computing device, wherein the clock update token is indicative of an authority of the computing device to update the real-time clock of the access control device;
• authenticate the clock update token based on at least the session random value;
• and
• update the real-time clock based on a received update time in response to successful authentication of the clock update token.

A method, comprising:

• transmitting, by an access control device and to a computing device, at least one wireless communication message that identifies a clock status of a real-time clock of the access control device and a session random value, wherein the clock status includes a clock status value indicating that the real-time clock is inaccurate;
• receiving, by the access control device, a clock update token from the computing device, wherein the clock update token is indicative of an authority of the computing device to update the real-time clock of the access control device;
• authenticating, by the access control device, the clock update token based on at least the session random value;
• and
• updating, by the access control device, the real-time clock based on a received update time in response to successful authentication of the clock update token.

One or more non-transitory machine-readable storage media comprising a plurality of instructions stored thereon that, in response to execution by an access control device, causes the access control device to:

• transmit at least one wireless communication message that identifies a clock status of a real-time clock of the access control device and a session random value to a computing device, wherein the clock status includes a clock status value indicating that the real-time clock has not been set after a reset event;
• receive a clock update token from the computing device, wherein the clock update token is indicative of an authority of the computing device to update the real-time clock of the access control device;
• authenticate the clock update token based on at least the session random value;
• and
• update the real-time clock based on a received update time in response to successful authentication of the clock update token.