Simple encryption proposal. Comments ?

[Paul Rubin]

bokr at oz.net (Bengt Richter) writes:
> Thanks for posting, mine was in C++ and not so pretty (though fast enough ;-)
> 
> BTW, (untested)
> 
>     k1, k2, k3 = map(_inv_letters.__getitem__, x[i:i+3])
> 
> might be an interesting alternative to the list comprehension?

I don't know, I wasn't really trying to make that function fast, I was
just playing around.  Base52 is a clever idea (I've gotten burned a
number of times by non-alphanumeric base64 characters needing escaping
for some purpose) so I wanted to try it.  A more serious
implementation should be done as a C patch to the binascii module.

I also sometimes use base 32 (5 bits per output character) which is
just monocase letters plus digits.  The letters O and S, and the
digits 0 and 5, are omitted, since they're hard to tell apart from
each other in handwriting.