-----BEGIN PGP SIGNED MESSAGE----- David Stoler recently commented:

I ftp'd the Blowfish implementation from ftp.ox.ac.uk and ran some benchmarks.

Encryption and decryption are faster than the fastest DES implementation I've found, but the key expansion (subkey generation) is slow.

On a 100 Mhz PowerPC I get the following results:

Key expansion: 350 keys per second = 3.33 milliseconds per key

Encryption/Decryption: 190,000 8 byte blocks per second = 5.26 microseconds per block

This is 40% faster (encryption/decryption) than the best DES I have.

Questions: ... 3. Is there a way to improve key expansion performance for applications that change keys frequently? (Other than caching expanded keys...)

Actually this (slow key expansion) is a feature. It limits the speed of a brute-force attack, since each new key to be tried must be expanded. What applications need to change keys more than once a second? I'd also be interested in comparisons of Blowfish to IDEA. Edgar W. Swank <EdgarSwank@Juno.com> (preferred) Edgar W. Swank <Edgar_W._Swank@ilanet.org> Edgar W. Swank <EdgarSwank@Freemark.com> Home Page: http://members.tripod.com/~EdgarS/index.html -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMr4fSt4nNf3ah8DHAQHycwP7BWTgyHVVZrtEhlMQKmSFFQGcMKqxaa5V y7D0OSVGTuddkwFDsVR7Qt3YGV0q3sMWbXFbicn2R/25rBbFNzA8d2rdgIxJVEzZ 0uKb1xdWkVR7GLIlQDciQW/zdQxdXjkiQ9sVbUJtPwYzUdZt6us3Izac1FZ4fKAX mvlqa4yWG58= =Tmc6 -----END PGP SIGNATURE-----