Only three of the many encrypted postcards I have covered on this blog so far have remained unsolved. The one I am going to introduce today might be number four.


In 1934, a US magazine published an encrypted message a reader had found in an old document. The solution is not known to me.


Two postcards from the early 20th century are written in Morse code or something similar. One of these cryptograms is still unsolved.


A Facebook user has posted a number of scans of a 19th century pocket lexicon with about 80 pages of code in it. Can a reader solve it?


A medal that is depicted in a Freemason document from 1952 bears two encrypted inscriptions. Can a reader decipher them?


In 1905, an encrypted postcard was sent from San Francisco to Paris. Can a reader break it?


In the New York Public Library, I found a cryptogram from 1925. The cleartext could be the Declaration of Independence. I wonder who created this document and why.


Around 1920, a US pulp magazine published an encrypted message exchange in its “missed persons” column. The cleartexts might refer to a familiy drama. Even two of the world’s greatest codebreakers apparently could not make sense of these cryptograms.


In 1863, during the US Civil War, a Union soldier wrote a letter to an unknown recipient. This letter is encoded in a shorthand, probably Pitman. Can a reader decipher it?


The US Navy cryptologists use a logo that contains an encrypted message. Can a reader decipher it?