This project utilized the well-established Z408 Cipher key which was verified by the FBI in 1969.
The Z340 and later Zodiac ciphers used a set of additional symbols for encryption. The letters assigned to these new symbols were determined by a procedure outlined in the two books. The results of that process are presented in the diagram below.
These assignments were used for all the Zodiac cipher solutions in this body of work. This imposed restraints on what the cipher solutions could be. In spite of these constraints, viable, informative solutions were found.
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