They have not released their source code for independent evaluation. I for one would feel a lot more comfortable with DESChall if there was at least some outside review, even if no general release is made.
I do not keep up with the various DES challenge efforts: Did DESChall ever give a reason for not releasing source code? Has anyone tried reverse engineering the executable? Does anyone have statistics on how quick deschall is as opposed to, for example, Bryddes? If they haven`t released source code and it is significantly faster it may be they have further key schedule optimisations they do not wish to share. Datacomms Technologies data security Paul Bradley, Paul@fatmans.demon.co.uk Paul@crypto.uk.eu.org, Paul@cryptography.uk.eu.org Http://www.cryptography.home.ml.org/ Email for PGP public key, ID: FC76DA85 "Don`t forget to mount a scratch monkey"