In September 2005, Canada's former Foreign Service Communicators held a reunion in Ottawa. Foreign Affairs Canada kindly loaned some materials and exhibits for use during the reunion. These vintage "tools of the trade" are illustrated below along with explanations of their development and use.

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BOOK CYPHERS IN EXTERNAL AFFAIRS CANADA (1930’s – 1980’s)
By David Smith

OTFP and OTLP were the successors to systems such as the Government Telegraph Code (GTC). GTC was a low-level restricted document, similar to OTFP where one simply looked up the desired word and wrote down the corresponding code. The real purpose was a means of saving on words and thus commercial cable costs. GTC was the forerunner and basis for the idea of an OTFP cypher. An interesting aside is the story of when Morse code operators had to transmit Chinese characters. With 10,000 characters in existence, (most Chinese I discovered during an assignment in Beijing knew only 2,000 to 4,000 characters), operators needed a means of converting the Chinese characters to Morse.

Numbers from 000 to 9999 were assigned which meant the originator had to convert to numbers while the recipient had the task of converting back to characters. I watched this process in Beijing when commercial cables were delivered to the Canadian Embassy and our local Chinese staff would do the converting back to Chinese characters – and then most likely to English for the Canadian staff. Like GTC, OTFP was a completely manual encryption method used by External Affairs (EA) and others from the 1930’s until it was phased out in the 1980’s. In the beginning, EA used British code books and pads until the 1950’s when Canada began using “Canadian” Encode/Decode books and pads. The first editions produced (numbers 001) are inscribed by the then Secretary of State for External Affairs, Lester B. Pearson, with the notation “Finally we have our own Cypher system”.

One time figure and letter pads had sealed edges. The seal was a soft plastic but rubbery membrane and the operator would only be authorized to unseal the page or pages required to encode or decode a particular message. The lower right-hand corners of the pads were not sealed so the communicator could slip a double edged scribe (knife) into the open corner and slide it upwards and then to the left to cut open one page at a time. Each page was numbered and this number, along with the serial number of the pad would be the first two five-figure numbers encoded to verify to the receiving operator which book and what page number was being utilized. Where needed, zeros would be added to make up five figures. Line numbering was not used. A new page was required for each new message, regardless of the length.

Encode and decode pads were produced as “2-way” or “3-way” and multi-way within certain geographical areas, the UN, or Commonwealth countries. 2-way pads were used between External Affairs headquarters in Ottawa and one other mission (Embassy or High Commission). Three-way encryption pads would allow use by two overseas missions. Most missions used two-way pads between their location and HQ. Pads were assigned either an “IN” or “OUT” designation. IN pads were used for decoding messages and OUT pads were used for encoding messages.

OTFP's