Modified amino acid compounds useful in the delivery of active agents are provided. A transceiver may include a matching circuit that is coupled to an antenna and includes an adjustable capacitor. The program preferably includes socket layer, channel layer and message handling layer components for permitting and extracting communications over a network. The storage unit may have a penetration hole through which the main axis is inserted when the opening unit is closed. The token vault computer may receive the token, a current time, and a credential identifier.