A cryptographic device comprises a data stream interceptor, a main controller receiving input from the data stream interceptor, and a pair of data generating and storage controllers adapted to perform data transfer protocols with corresponding peer controllers of a data generating device and a data storage device, respectively, on command from the main controller. The cryptographic device further comprises a cipher engine programmed to transparently encrypt and decrypt data streams flowing between the data generating device and data storage device on command from the main controller. The cryptographic device does not utilize system resources associated with the data generating and storage devices during operation.