It may be easiest to just let Wikipedia explain the background of the Nihilist Cipher: In the history of cryptography, the Nihilist cipher is a manually operated symmetric encryption cipher originally used by Russian Nihilists in the 1880s to organize … Continue reading
AMSCO is an incomplete columnar transposition cipher. A bit to unpack there, but basically that means that you’re putting the message into columns and those columns may not have equal lengths. It was invented by an A.M. Scott in the … Continue reading
A couple of months ago the NSA’s Facebook and Twitter accounts posted this image, alongside the message “Can you crack the code? Check back Thursday for your next clue”: