Almost thirty years ago, I used to use pkzip (on MS DOS) to compress and encrypt a bunch of personal files that I worked on every day but on different PCs. Every day, I would unpack my stuff (from a floppy disk), make whatever updates throughout the day, then re-encrypt/recompress the whole mess back onto the floppy so I'd have it the next day. Then one day I must have made a typo when entering the encryption password - and I must have entered it incorrectly the same way twice because it used it to encrypt the archive. I've tried every permutation of the original password that I could think of, with capslock on and with it off and have never been able to crack that file. I suppose by now I have the horsepower to brute force it, but what a PITA! And, after all these years, the data will no longer be relevant.
