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A postcard from 1903 is encrypted in a dancing men code, like it is described in a famous Sherlock Holmes story. Can a reader decipher it?

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A Reddit user has posted photos of an unusual machine, the purpose of which is unknown. Some say it might be an encryption machine. Can a reader tell more about it?

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A fifth encrypted bottle post has been found in the river Alster in Hamburg. Still, nobody seems to have a clue what these strange messages mean.

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Two important events took place in the London area yesterday: the royal wedding and the “History of Cryptography and Codes” conference (including a presentation given by me). Hundreds of thousands of people came to see these two spectacles.

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Here’s a postcard written in English that contains two kinds of encryption. Can a reader decipher this two-part cryptogram?

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18-year-old chemistry student Paul Rubin was found dead with a cyanide poisoning in 1953. In his possession police found an encrypted message. This cryptogram has never been deciphered.

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LC4 is a cipher that can be computed by hand. According to its creator, it is both secure and easy to use. Is LC4 better than other low-tech ciphers I have introduced on this blog?

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Here’s another crypto postcard. As the encrypted part of the message has only 17 letters, it is probably hard to decipher.

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Encrypted gravestones are rare, and they have a morbid charm. Here is one located in a town between Liverpool and Manchester. Can you decipher its encrypted inscription?

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The Würzburg Residence is one of the most famous castles in Germany. A painting inside shows an encrypted inscription. The solution of this cryptogram is not known to me.