Cryptanalysis of the Enigma by the letters on the top row of the Enigma keyboard. So, "continuation of message sent at 2330" was represented as "FORTYWEEPYYWEEPY". "Cribs" were fundamental to the British approach to solving Enigma keys, but guessing the plaintext for a message was a highly skilled business. So in 1940 Stuart Milner-Barry set up a special "Crib Room" in Hut 8. Foremost amongst the knowledge needed for identifying cribs was the text of previous decrypts. Bletchley Park maintained detailed indexes of message preambles, of every person, of every ship, of every unit, of every weapon, of every technical term and of repeated
Mass surveillance in the United Kingdom and metadata for 30 days. A number of other GCHQ operations were revealed, including hacking into telecoms equipment, access to fibre-optic cables and programmes operated jointly with the NSA. GCHQ was originally established after the First World War as the "Government Code and Cypher School" (GC&CS) and was known under that name until 1946. During World War II, staff including Alan Turing worked on decoding the German Enigma machine, and many other foreign systems. In 1940, GC&CS was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems. After World War II, the United Kingdom