High-speed Hardware Design for the Twofish Encryption Algorithm
Choong-Mo Youn, Beom-Geun Lee · Journal of information and communication convergence engineering · 2005
Twofish is a 128-bit block cipher that accepts a variable-length key up to 256 bits. The cipher is a 16round Feistel network with a bijective F function made up of four key-dependent 8-by-8-bit S-boxes, a fixed 4by-4 maximum distance separable matrix over Galois Field, a pseudo-Hadamard transform, bitwise rotations, and a carefully designed key schedule. In this paper, the Twofish is modeled in VHDL and simulated. Hardware implementation gives much better performance than software-based approaches.