Bletchley code breaker Betty Webb dies aged 101

Any good book that delves into the detail of the code breaking done at Bletchley park?

The Hut 6 Story, goes into enough detail that Gordon Welchman (Simply put, Turing's boss) lost his security clearance. If you care about the human side, but are keen to take on the details there's no better book possible.

If you would enjoy loosely related fiction, Neal Stephenson Cryptonomicon is an option I would personally recommend. You must have some tolerance for his particular style and content…

"The Theory that Would Not Die" by Sharon McGrayne has a good chapter on this, book is a more general history of Bayesian statistics.

This is a great book and touches on the subject you mention https://simonsingh.net/books/the-code-book/

Having read this book, I set some codes for my son to break. Each code, once broken, told him the location of the next coded message. And they got progressively harder. It was a fun challenge.

The author of this book also runs an excellent weekly maths newsletter/quiz for 11-16 year olds, and it's free:

https://parallel.org.uk/parallelograms

Or Enigma by Robert Harris.

Another vote for The Hut Six Story.

The title includes ‘Six’ not ‘6’ (not that it should trip up a search algo, but you never know)

Apparently some computers still aren't able to crack the simplest encryption schemes.

If you want a book in the same vein, and contemporary with Bletchley "Turning's Cathedral" by George Dyson is about the Institute for Advanced Study and the Manhattan Project. Needless to say there's a lot of overlap and it really defines the culture of computer engineering at the time.

On the American side, "The Woman Who Smashed Codes" by Jason Fagone is really good.