The RC algorithms are a set of symmetric-key encryption algorithms invented by Ron Rivest. The "RC" may stand for either Rivest's cipher or, more informally, Ron's code.[1] Despite the similarity in their names, the algorithms are for the most part unrelated. There have been six RC algorithms so far:
- RC1 was never published.
- RC2 was a 64-bit block cipher developed in 1987.
- RC3 was broken before ever being used.
- RC4 is a stream cipher.
- RC5 is a 32/64/128-bit block cipher developed in 1994.
- RC6, a 128-bit block cipher based heavily on RC5, was an AES finalist developed in 1997.