What is Blowfish?
Q: What is Blowfish?
A: Blowfish is a keyed, symmetric block cipher that was created in 1993 by Bruce Schneier. It has been included in many encryption products since then.
Q: What was Blowfish made for?
A: Blowfish was made as a general-purpose algorithm to replace the old DES algorithm and to remove the problems and difficulties of other encryption algorithms.
Q: How long can the key length be for Blowfish?
A: The key length for Blowfish can range from 0 up to 448 bits.
Q: What are some features of the design of Blowfish?
A: Some features of the design include key-dependent S-boxes and a very complex key schedule.
Q: Is there any known cryptanalysis on the full-round version of Blowfish?
A: As of 2008, there is no known way to break the full 16 rounds apart from a brute-force search.
Q: What type of attack did Serge Vaudenay find against Blowfish?
A: Serge Vaudenay found a known-plaintext attack needing 28r + 1 known plaintexts to break, where r is the number of rounds. He also found a class of weak keys that could be detected and broken by this same attack with only 24r + 1 known plaintexts.
Q: Does Bruce Schneier recommend using Twofish instead of Blowfish now?
A: Yes, Bruce Schneier recommends using Twofish instead of Blowfish now due to its improved security measures compared to older algorithms like DES or even newer ones like AES.
