A communication device receives secure communication frames on which a security transform has been performed to permit authentication. The communication device maintains an authentication history and a local time varying parameter. In multi-hop communication, the communication device provisionally verifies the freshness of a received secure communication frame by verifying that identifying information extracted from the frame is not already present in the authentication history and that a received time varying parameter extracted from the frame is not older than the local time varying parameter by more than a certain margin. If these freshness tests both pass, the frame is authenticated. If authentication succeeds, the frame is transmitted on the next hop without performance of a new security transform.