Column Ciphers

Column Ciphers, or Poem ciphers have been in use by the intelligence services for some time. Like one time ciphers they require shared knowledge of


Secret words and secret messages

There are a variety of ways you can get hidden messages into ordinary messages. Acrostic poems are the most common example of this – where


Vigenère cipher

A Vigenere cipher is a form of letter substitution cipher that is incredibly difficult to break. It operates by changing the cipher shift number on


Caesar Ciphers

Caesar ciphers are one of the earliest known and simplest ciphers we use in Cosykiller. They are very common and it is probably one of


Directional codes

Directional codes are probably some of the easiest codes to work with in Cosykiller. These codes rely on you reading the text in a way


One Time Cipher Pads

One time Cipher Pads are one of the hardest ciphers to solve, and yes – sorry – they do crop up in cosykiller. One Time


Breaking Letter Substitution codes

A Letter Substitution Cipher replaces the letters in the alphabet with symbols or another random letter. An example of a letter substitution cipher can be


Knock Code

Knock Codes, sometimes called Tap Code come up intermittently in our Cosykiller boxes. The example below is a telegram written with a classic Knock Code