The second cipher , which used several different symbols for each English letter in the text, was much more difficult.
An equivalent way of writing the same cipher is shown in the diagram.
The first cipher broken was Serpent: the cipher universally considered to be the safest, most conservative choice.
Astrid throughout remains a mere cipher , a beautiful woman with a crooked smile whom the narrator met while he was a student.
Jim is an expert at classical cryptography and has written a program that is quite good at cracking Enigma cipher .
A Second World War code cipher book won't help!
Julius Caesar used a substitution cipher , now known as the Caesar Shift Cipher, where messages were encoded by replacing each letter in the alphabet with the letter three places along.
It became a vital tool for the Nazis during World War II who used it to cipher and decipher secret messages.
The enciphering and deciphering of messages in secret code or cipher is called cryptology.
Among the drawings are masterpieces by Rex Whistler, whom the Queen Mother also commissioned to design a new royal cipher .