cryptogram
An encrypted message whose content can only be read by someone who breaks the code
A cryptogram is a text in which the actual content is concealed by encryption — that is, letters, numbers or symbols have been replaced by other characters according to a particular system, so that the message can only be understood by someone who knows the code or is able to break it. The concept is not an independent legal category in Danish law, but is used in criminal cases as a designation for the encrypted messages an offender leaves behind or sends.
In a true crime context, cryptograms are particularly associated with the Zodiac Killer, the unidentified serial killer who in the late 1960s and early 1970s sent encrypted letters to Californian newspapers and the police. The letters contained sequences of symbols — a mixture of letters, numbers and invented characters — that were said to reveal the perpetrator's identity or his motives.
Criminal investigation involving cryptograms requires cooperation between the police and code breakers, and the solution of such a code can have direct evidentiary value in a criminal case. The Zodiac cryptograms have been partially deciphered by amateur code breakers, while other parts remain unsolved, making them a central element in the decades-long course of the investigation.
