paper

  • 15th January 2026

Old pencil and paper cryptosystems.

As you may have seen from my site, I have long been interested in old pencil and paper cryptosystems, even before getting hooked on computers. Over the years, I have re-implemented a few of them in various languages:

  • Old BASIC on my Sinclair QL like ages ago
  • Like 15 years ago in Ruby
  • Then in Go when I learned the language in 2016
  • And more recently in, what else, Rust
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