A media access control (MAC) security (MACsec) function block may implement MACsec protocols on a network. A physical layer device (PHY) may connect to the MACsec function block and an interface register configured to store command information for the MACsec function block. A central processing unit (CPU) may provide the command information for the MACsec function block to the PHY via a management data input/output (MDIO) bus. The PHY may execute either a read command or a write command against the MACsec function block based on the command information, receive, from the MACsec function block, a response corresponding to the execution of the read command or write command against the MACsec function block, and provide the response to the CPU via the MDIO bus.