An investigator pinning suspect portraits and cipher notes to an evidence board

The casebook 8 entries

How the codes
come apart.

Every case file hides its secrets behind a cipher of one kind or another. These are the working notes: what each code is, where it came from, and the method that cracks it.

Put it into practice

Reading about ciphers is one thing.
Solving one is another.

Every technique on this page turns up somewhere in a Cosykiller box — usually when you least want it to.