"Serpent was designed by Ross Anderson, Eli Biham and Lars Knudsen as a candidate for the Advanced Encryption Standard. It has been selected as one of the five finalists in the AES competition. Serpent is faster than DES and more secure than Triple DES. It provides users with a very high level of assurance that no shortcut attack will be found. To achieve this, the algorithm's designers limited themselves to well understood cryptography mechanisms, so that they could rely on the wide experience and proven techniques of block cipher cryptanalysis. The algorithm uses twice as many rounds as are necessary to block all currently known shortcut attacks. This means that Serpent should be safe against as yet unknown attacks that may be capable of breaking the standard 16 rounds used in many types of encryption today. However, the fact that Serpent uses so many rounds means that it is the slowest of the five AES finalists. But this shouldn't be an issue because it still outperforms Triple DES. The algorithm's designers maintain that Serpent has a service life of at least a century."

"Serpent is a 128-bit block cipher, meaning that data is encrypted and decrypted in 128-bit chunks. The key length can vary, but for the purposes of the AES it is defined to be either 128, 192, or 256 bits. This block size and variable key length is standard among all AES candidates and was one of the major design requirements specified by NIST. The Serpent algorithm uses 32 rounds, or iterations of the main algorithm."