Hamster-Sendezeiten-2-bar

A recent TV documentary reported on a spy radio transmitter that was placed near an East German army facility. The transmission schedule of this device was computed with a method that is not publicly known. Can a reader reverse-engineer this algorithm?

Diary-Manic-Fuzz-bar

Today I am going to introduce two encrypted diaries. Only one of these is solved. Can a reader decipher the other one?

Postcard-Melton-Mowbray-bar

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.

Bauch-Code-Solved

US artist Andy Bauch hid messages in his Lego artworks. Blog reader Christian Baumann has now solved two of the codes.

Adventure-2-bar

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

Postcard-Plymouth-bar

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

Vest-Lexicon-bar

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?

Civil-War-Era-Bovine-bar

The Museum für Kommunikation in Frankfurt owns a cipher tool from the 19th century. Not much is known about it. Can a reader find out more?

Bauch-bar

US artist Andy Bauch has created Lego mosaics that encode money in BitCoins and other crypto-currencies. Can a reader break his codes?

Freemason-Medal-bar

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