Hi all --

I'm looking for a function, F(i), that takes an integer argument, i, in the range 1 .. 10^8 and returns a short string, say 8 characters long, using the 26 + 26 + 8 = 60 character set ‘A’..’Z’, ‘a’.. ‘z’, ‘2’ .. ‘9’. (I want to omit ‘0’ and ‘1’ to avoid ‘O’ and ‘l’ confusion).

F(i) must be invertible – that is, each unique i maps to a unique F(i), and each unique F(i) maps to a unique i. And I don't want psuedo-random function (eg just build up a random string then cache it to a file or a DB to ensure that string is not reused); I'm lookling for something deterministic.

The number of valid strings (10^8) is much less than the number of possible strings (60^8), so the chance of guessing a correct string is extremely low.

Do you have suggestions for doing this in perl? Do I want a MD5 hash or something? If there is a canned algorithm that is pretty close to this, I can change my requirements somewhat. I would prefer to keep the strings short to keep 'em human friendly.

Thanks, wise monks, for any tips and pointers --

rkg

In reply to perl / math: integer obfu by rkg

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