Co-wrote the StreetPerformerProtocol with BruceSchneier.

From the bottom of the StreetPerformerProtocol:

''John Kelsey is a cryptographer at CounterpaneSystems, co-designer of TwoFish and YarrowAlgorithm, and the author of dozens of academic papers on cryptography. E-mail: mailto:kelsey@counterpane.com''

[Links mine. -- SunirShah]