Even in the internet era where members of ISIS and other terrorist groups have been found to use Sony’s PlayStation 4 as a communication tool, one relic of the Cold War is still very much active. It is the “numbers station,” a shortwave radio station that broadcasts seemingly random number sequences – only the numbers reveal a code that spies use to receive messages from their governments.
The numbers were used with a “one-time pad” encryption, and thus nearly impossible to crack without a code book. Unlike other forms of encryption, the numbers were broadcast in the clear on the shortwave band, which is well above the normal AM/MW frequencies.
While number stations are largely associated with the Cold War, this form of communication actually dates back more than 100 years when the first messages may have been sent to Archduke Anton of Austria during the First…
