The United States created a secret peacetime Black Chamber, called the Cipher Bureau, in 1919.

The Cipher Bureau entrusted the design and construction of the equipment to AVA.

The title of the book refers to the Cipher Bureau, the cryptographic organization of which Yardley was the founder and head.

The Cipher Bureau was becoming irrelevant.

In mid-1931, the Cipher Bureau was formed by the merger of pre-existing agencies.

In the summer of 1932, the Poznań branch of the Cipher Bureau was disbanded.

In 1937 the Cipher Bureau moved to the Kabaty manor.

Polish Cipher Bureau in the 1980s, Cryptologia 32(4), October 2008, pp.

His description of the pioneering work done by Poland's Cipher Bureau before the war is minimal and incorrect.

It was only after they had handed over details to the Polish Cipher Bureau that progress was made.