I saw that, and supposed at the time it was a Perl implementation of the Vigenère cypher, probably because your chart was formatted as a square. Looking again now, it seems to be just a simple 8-way Ceasar cypher, which I guess is the same in principle with a 8-character password built-in rather than allowing the user to supply a password.

It will be trivially cracked. You can suppose that files end in ".exe" etc., and very often have dot as the 4th from the end character. Since the encoding rule depends on the mod-8 position, various length filenames will allow you to probe the cypher and get a few matches. From there you can pick out bits of words, and continue the process.

Hmm, I wonder if the old Vigenère or other substitution cypher could be used in a chaining mode...?

—John

In reply to Re-3: Encrypting a Filename by John M. Dlugosz
in thread Encrypting a Filename by John M. Dlugosz

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