Blog reader Norbert Biermann has recently solved a bigram substitution ciphertext consisting of 1346 letters – the shortest one ever broken. Here’s a 1000-letter ciphertext of the same kind.
During a stay in the Austrian capital of Vienna, I tried to take a look at the encrypted inscription on the cenotaph of Duke Rudolf IV. I was only partially successful.
In 1920, IRA member Patrick James McGuire received an encrypted Easter postcard. Does it contain a love message? Or is the content related to the Irish War of Independence?