NKRYPT is a set of eight steel pillars bearing encrypted inscriptions, located in Canberra Australia. Here are a few photographs of this artwork, along with some basic information.

A museum director from Switzerland is asking for help. Can a reader decipher the inscription on an executioner’s sword?

In 1648, English king Charles I wrote four encrypted letters while in captivity on the Isle of Wight. Can a reader break these cryptograms?

Here’s a French letter from the 17th century, encrypted probably in a homophonic system or a nomenclator. Can a reader decipher it?

A 1911 book about forensic science depicts a cryptogram. Can a reader solve it?

Postcard enthusiast Günther Hunger from Oschatz has provided me a scan of an encrypted message from the early 20th century. Can a reader decipher it?

About 110 years ago, a Mariechen Schäfer living in Frankfurt, Germany received an encrypted postcard. Can a reader solve it?

Two months ago, US book author A.J. Jacobs showed me the encrypted journal of psychologist Abraham Maslow (1908-1970). My readers did a good job in analyzing this cryptogram. Now, A.J. asks for additional help.

In 1943, the British intecepted an encrypted radio message sent from an airplane. Can a reader decipher it?

In 1908, an ecrypted postcard signed with “Somebody” was sent to a sobriety organisation in Northern Ireland. Can a reader decipher it?