| The great French cryptanalyst Georges J. Painvin succeeded in cryptanalyzing critical ADFGVX ciphers in 1918, with devastating effect for the German army in the battle for Paris. |
| This was discovered by an astute cryptanalyst at Central Bureau and in April 1943 that code was broken. |
| Alan Mathison Turing was an English mathematician, logician, cryptanalyst, and computer scientist. |
| During the Second World War, while working as a cryptanalyst for the Department of National Defence, he completed his MA and PhD in French at the University of Ottawa. |
| During World War II, Turing was a leading cryptanalyst at the Government Code and Cypher School in Bletchley Park, Buckinghamshire, England. |
| Correlation between the secret key and the output of the cryptosystem is the main source of information to the cryptanalyst. |
