"Cracking the Code" is an 8-part documentary series that just dropped on Curiosity Stream. Episode 2 is dedicated to the Zodiac Killer codes and features the solution of the famous 340 cipher. The other episodes feature many fascinating codebreaking stories, such as mob codes, Japan's "unbreakable" WWII code, mysterious ancient languages, and more.
https://therokuchannel.roku.com/details/a28b8af726d3566b81f473229cfeb6d6/cracking-the-code
https://www.televisual.com/news/blink-films-cracks-code-for-curiosity
