by nickfarr, published
The Polyalphabetic Substitution Cipher Slide Rule. This is a slide rule to assist with the ciphering and deciphering of polyalphabetically enciphered messages. With it, you can learn a bit about how slide rules work and a bit about crypto at the same time! It also has some added features that let you begin exploring strong crypto.
You can make two PSRs out of one piece of 12"x12" material. There's no waste leftover with this design!
The PSR is essentially three pieces, the slide, the body and the indicator. The body consists of a top and bottom stator which cradle the slide. The indicator goes on top of the body and slide.
Glue the top row of letters (top stator) and the bottom row of numbers (bottom stator) to the body. Then glue together the indicator. The indicator should slide over the base. VoilÃ ! Now get to ciphering!
The PDF should help make things clearer.