The challenges of Giouan Battista Bellaso were one of the top unsolved crypto mysteries. Norbert Biermann has now published the last two parts of the solution.


Two encrypted letters written by Spanish king Ferdinand II of Aragon baffled historians. Thanks to secret service codebreakers, the mystery is now solved.


Israeli codebreaker and reader of this blog, George Lasry, has solved cryptogram #42 from my top 50 list.


Three weeks ago I introduced Ernest Rinzi’s encrypted journal – one of the most spectacular cryptograms I have ever seen. London-based codebreaker Tony Gaffney has now broken a large part of the cipher. Maybe a reader fluent in Italian can fill in the gaps and supply a translation.


A few weeks ago I introduced two unsolved encrypted letters from the Thirty Years’ War. Scientist and blog reader Thomas Ernst has deciphered them now.


A 17th-century Italian nun claimed that the Devil had dictated an encrypted letter to her. Scientists have now allegedly broken this cryptogram. Details are not known yet.


Some of the crypto mysteries I recently introduced on this blog were quite tough. As a change, here are a few easier ones from a 19th century children’s magazine.


Italian cryptologist Luigi Sacco left behind a text encrypted with a Fleissner grille. Paolo Bonavoglia and Bart Wenmeckers, both readers of this blog, solved it.


In a British censorship manual from WW2 two pictures containing hidden messages are displayed. My readers have now found at least a part of the solutions.


Three weeks ago I blogged about an encrypted telegram that was sent from New York to Tel Aviv in 1948. This cryptogram has now been solved.