During the military dictatorship in Uruguay in the 1970s and 1980s, three encrypted documents were sent between members of the urban guerrilla MLN Tupamaros. In this work we present the second of these documents, whose text was encrypted by an array of colored circles on the covers of a book.
We introduce some of the history and the processes of image recognition and decryption of this document.
Keywords: substitution cipher Uruguay Tupamaros decryption Eva
Proceedings of the 2nd International Conference on Historical Cryptology, HistoCrypt 2019, June 23-26, 2019, Mons, Belgium
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