BlackBond E1 by Engage Black is a circuit encryption device designed to seamlessly encrypt E1 and fractional E1 circuits. It utilizes 256-bit AES encryption to protect data in motion across various network environments. BlackBond E1 operates as a 'bump in the wire' device, allowing it to encrypt circuits without impacting voice, video, and data E1 traffic due to its extremely low latency. It automatically rotates cryptographic keys at user-defined intervals and uses a FIPS-compliant Random Number Generator (RNG) for key generation.