Wirt writes:
> For this kind of application, we can generate a encryption routine that
> will be essentially unbreakable, so long as we don't tell anyone what
> the algorithm is.

With all due respect, this is unlikely.  You can do something to
"obfuscate" the data stream so that it does not appear to be plain
text, but any "do it yourself" encryption algorithm is almost
always no better than a relatively simple obfuscation, no matter
how much clever code or mathematical churning you put in.  That is,
the cost to figure out a relatively simple obfuscation is probably
not much less than that to break a "high-powered" do-it-yourself
encryption algorithm.

G.