olemus
plokkšiffer (B. Schneier jt, 1998), Blowfishi edasiarendus, AES-võistluse finalist; plokk on 128-bitine, võtmepikkusega varieeritav
= a 128-bit block cipher that accepts a variable-length key up to 256 bits

ülevaateid
https://en.wikipedia.org/wiki/Twofish
https://csrc.nist.rip/encryption/aes/round1/conf1/twofish-slides.pdf
https://thesai.org/Downloads/Volume14No3/Paper_44-A_Comparative_Study_of_Twofish_Blowfish_and_Advanced_Encryption.pdf