I've always been fascinated with codes and ciphers. Shift and substitution ciphers were especially intriguing to me. Like many in the earlier days of the internet, I stumbled upon declassified Army field manuals. Due to my interest in ciphers, I frequently referenced the Word and Pattern Tables inside Army FM 34-40-2. I don't claim to have created the data in this repository. This is data made public by the United States Government. Since it does not quite adhere to the OPEN Government Data Act's "machine-readable data" principle, I have taken it upon myself to publish pieces of the data from FM 34-40-2 in json format.
There are a lot of better data sets out there for cryptanalysis. This data is being provided so that others like me, those curious how well this old data holds up, can test it out.