An electronic control unit (ECU), or node, is configured to use a single key for all virtual ECUs (V-ECUs) having a message to transmit. The ECU also may include a security peripheral that includes the stored shared key. The security peripheral may further include a policy enabling it to detect if a request from the V-ECU is valid, in which case it generates a MAC. The security peripheral is also used to store information in a MAC Generate Allow List (MGAL), which may define the policy about when the V-ECU can transmit. The ECU may include a crypto-engine, which stores shared keys from other nodes used to verify MACs transmitted by other nodes.