Speed Comparisons of Block Ciphers on a Pentium
Algorithm	Clock cycles per round	# of rounds	# of clock cycles per byte encrypted	Notes
Blowfish	9	16	18	Free, unpatented
Khufu/Khafre	5	32	20	Patented by Xerox
RC5	12	16	23	Patented by RSA Data Security
DES	18	16	45	56-bit key
IDEA	50	8	50	patented by Ascom-Systec
Triple-DES	18	48	108

Schneier.com is a personal website. Opinions expressed are not necessarily those of BT.