Clocking in at over 900 pages, Neal Stephenson's Cryptonomicon tops the list of longest books I've ever read, surpassing the 840 pages of Stephen King's Needful Things, which I read twice. I stumbled upon the 1999 bestseller while researching cryptocurrencies, but there's no mention of Bitcoin founder Satoshi Nakamoto to be found. Instead you'll find a sprawling tome spanning the latter half of the 20th century, and many if not all the mentions of "crypto" refer to cryptography: the ability to securely send and receive messages in the presence of adversarial third parties. There's a fascinating scene where jailhouse neighbors, being expert cryptographers, exchange messages through a system unlocked by a deck of playing cards.
The plot spans several generations, but a partial summary would be the daughter of an American soldier (whom you meet early in the novel) helps a startup telecommunications company to uncover a secret Japanese gold mine using the pretense of wanting to lay an undersea cable. Along the way you also meet the mine's central engineer/ architect and acquire more knowledge about mine construction than most people will uncover in their lifetime. I love writers who keep their novels learning-adjacent.
A six-week, one-renewal loan period from LA Public Library was not enough time for me to finish Cryptonomicon so I sprung for the Kindle version in early August. Stephenson himself said his books are simply too long to make good movies, so if you'd like to dig deeper on crypto without the currency I'd suggest watching 2014's The Imitation Game, the Saving Private Ryan of World War 2 computer movies.