In the Cold War days (and still today) US intelligence communicated with Russian agents through a variety of means. First of all, an agent is an asset and not a CIA employee. In Russia, an example of an agent was a defected KGB officer who was providing information to US intelligence. As it was imperative that the agent’s identity was kept secret, the CIA was forced to be extremely creative in delivering instructions. One such conduit was the One-Time Pad (OTP). An agent would use this column of numbers (only once as the name suggests) to match against a delivered batch of numbers and decipher a message. A way that this could work is if the agent would listen in to a certain frequency on a radio, during a certain time frame, and receive a batch of numbers. For example: He would listen for a sequence of numbers on his regularly tuned in radio station between 6:30AM – 6:40AM (during his ritualistic morning coffee). He would listen at the same time every day in order to maintain a cover and shield any reason for suspicion. When the day arrived that a span of numbers were conveyed he would write them down and match them with his OTP. Once deciphered the numbers would be changed to letters, ultimately revealing a message. Although there is a little bit more that goes into the OTP, this gives one an idea of how it works. Let’s try one!
This could have been made more interesting by utilizing numbers from a stat line on ESPN or possibly in the source code of a web page, but I want to make this as easy as possible. The way the OTP works is you receive a certain amount of numbers, and then match them above your numbers from the OTP. The batch of numbers is then separated in groups of five like this: 18411 87222. The OTP numbers (on bottom) will be subtracted from the received numbers (on top). This will be done by subtracting each individual number using a “non carrying” method of subtraction. A non-carrying method example is 1 over 9 which turns into 11 – 9 = 2. ( 2 over 3 turns into 12 – 3 = 9). As all the numbers are deciphered, you then would separate the numbers in groups of two in order to find the corresponding letter (03 = C, 22 = V, 01 = A, 13 = M, etc.) From here you put together the message, memorize it, and destroy it like Tom Cruise in Mission Impossible. So, I have included a short message underneath this paragraph with the numbers already received and placed above the OTP numbers. In order to read the message, write the sequences down on paper, subtract each individual bottom number from the individual number above, and then convert those results into letters. Refer to the below image if help is needed in working through the OTP message. Good luck! (Hint: the first letter is “C” = 03)
18411 87222 92560 99621
15369 67328 83350 68512
Wilks Wroasting 