Since you're playing devil's advocate...would one bit really be
sufficient for data mining?
Probably not, but 40 bits most certainly is.
guess it depends on how valuable the data is.
granted, it wouldn't take many encryption bits to make data mining
of usenet completely pointless...
somehow I don't view s/mime as being likely to be used in
broadcast media like usenet or mailing lists. I had the idea
that it's primary intended purpose was to provide privacy,
authentication, non-repudiation, etc for interpersonal mail.