Firefly is a U.S. National Security Agency public-key key exchange protocol, used in EKMS, the STU-III secure telephone, and several other U.S. cryptographic systems.
References
Firefly (key exchange protocol) Wikipedia(Text) CC BY-SA
Firefly is a U.S. National Security Agency public-key key exchange protocol, used in EKMS, the STU-III secure telephone, and several other U.S. cryptographic systems.