“Chief Security Officer”, my 24th book, has just been published. Contrary to my other publications, this one is a cartoon book. It tells funny, yet true stories about IT security.
According to a Reddit post, a needlework made in the 1980s contains a hidden message. The details are not known any more. Can you find this message?
From 1884-1887 a series of 25 encrypted newspaper advertisements was published in the “Daily Telegraph”. The key is known. Can you help me to decrypt these messages?
Four years ago I blogged about an encrypted (?) text a blog reader had found in an old school book. It is still unsolved. Meanwhile I have better scans and some additional information.
On Wikimedia, photographs of a number of lesser-known encryption devices from Switzerland are available. Can a reader tell me more about them?
The Siemens & Halske Geheimschreiber (T-52) was the second-most im portant encryption machine of the Germans in World War II. George Lasry has recently published a few computer-based attacks on this device.
A Rubik’s Cube can be used to define a crypto system that cannot be broken with quantum computers. Here’s a puzzle that shows the concept this system is built on. Can you solve it?
Here’s a strange cipher device: the front-side is a medal depicting St. George fighting a dragon, the rear-side is a cipher disk. Does a reader know anything about the background of this item?
Three encrypted newspaper advertisements from 1879 are still unsolved. Can you decipher them?
An evelope found in a stamp album contains two encrypted messages. Can a reader solve them?
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