Blog reader Christof Rieber has sent me a potential solution of a major crypto mystery: the encrypted passages of Lady Gewndolen’s diary. Is Christof’s deciphering attempt correct?
In 1914, a man sent an encrypted postcard from Kiel to Hannoversch Münden. Contrary to all other encrypted postcards I know, this one was written with a typewriter.
At the hacker conference 44CON 2019, wich took place in September in London, I gave a talk about Cold War cryptography. Here’s a professionally produced video of it.
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?
In 1873, an unknown person published two encrypted advertisements in the Daily Telegraph. Can a reader break these cryptograms?
At the NSA Symposium on Cryptologic History, I will give a presentation about brute-force attacks. There’s one thing I still haven’t figured out: when was the first brute-force described or carried out?
In 1916, a man living in Aschersleben, Germany, received an encrypted postcard. Can a reader decipher it?
Sometimes, deciphering a cryptogram is easier than reading the deciphered message. Here are two plaintexts I have difficulties to understand.