Harry’s 2023 Christmas Miscellany

It is an old tradition to produce a Christmas Almanac, or Miscellany, and while we make no great claims to originality we thought it would be worth joining in the fun. Some of the items below were suggested by competitors or long-time cipher challenge community members. Others are curiosities from Harry’s bookshelves. we hope you find something to enjoy here. Merry Christmas!

If you have your own suggestions for something we should add, why not let us know in the forum?

Madness suggested these pages on the Nihilist cipher

Absolutely nothing to do with codebreaking, but we love Cabin Pressure and we think you might enjoy the famous Christmas special! And if you want something more mathematical, you can always try the Logician’s Common room sketch!

Fancy some Christmas reading? How about the official 1950 Army field manual on cryptography, now declassified.

We added this pdf of Gaines’ book for the Christmas offering last year and we think a lot of you made good use of it. This year Madness has produced an errata for it, and we hope that Helen would not mind us publishing that here alongside her marvellous book.

If you like Sudoku, then we think you will love this! It was described as one of the best, by the amazing Cracking They Cryptic Team. We suggest you give it a go!

The Guardian have been publishing the King William’s College Quiz for years. It is devilishly difficult, but we have a feeling that the cipher challenge community might actually be quite good at “devilishly difficult things, so have at it!

In the completed puzzle the numbers 0 through 9 appear in each of the top six rows of the grid so that they give the column sums at the bottom and no number appears in twice in adjacent cells, including diagonal adjacency.

Some of you may remember this from 2020. The Letter Wriggler kindly wrote a series of grid puzzles for us, and this was one of the harder ones.

2023 – A whole year of mathematics on one page!

Quanta is one of our favourite magazines and in this article they review Maths in 2023.

2023 The Year of Machine Learning

2023 was the year that AI broke through to the public, and it even had an impact on the Cipher Challenge. (The poster was a collaboration between Harry and Midjourney.) While it is rather technical, you might want to take a look at this article written about the mathematics behind deep neural networks, commissioned for the 2022 International Congress of Mathematicians.