Lucifer (thing)

The American National Bureau of Standards was looking for a standard encryption system in the mid 70s. Lucifer, was an encryption system released by IBM developed by:

• Roy Adler
• Don Coppersmith
• Horst Feistel
• Edna Grossman
• Alan Konheim
• Carl Meyer
• Bill Notz
• Lynn Smith
• Walt Techman
• Bryant Tuckerman

On a side note: Horst Feistel frequently found himself in trouble with the NSA as he tried to perform research and development in Cryptography largely because he was a German immigrant, but also because the NSA didn't like other people working on cryptology period. At IBM's Thomas J. Watson Laboratory he was able to conduct his research for several years without problem.

Lucifer works on binary information, encrypting blocks of 64 bits at a time. Each block is encrypted seperately, being split in two, and then fed through through 16 'rounds'. A 'round' is described as:

L₀ (the first half block) and R₀ (the second half block). R₀ is mangled. The mangled 32-bit block is added to L₀ creating R₁. The original R₀ becomes L₁.

L₁ and R₁ are the inputs to the second round creating L₂ and R₂ and so on until 16 rounds have been completed. The result of the 16 the round is the encrypted Lucifer block.

Source The Code Book and delta's writeup on DES. Check delta's writeup to see what happened to Lucifer once the NSA got ahold of it.