Neal Stephenson - Cryptonomicon

In 1942, Lawrence Pritchard Waterhouse - mathematical genius and young Captain in the U.S. Navy - is assigned to detachment 2702. It is an outfit so secret that only a handful of people know it exists, and some of those people have names like Churchill and Roosevelt. The mission of Waterhouse and Detachment 2702-commanded by Marine Raider Bobby Shaftoe-is to keep the Nazis ignorant of the fact that Allied Intelligence has cracked the enemy's fabled Enigma code. It is a game, a cryptographic chess match between Waterhouse and his German counterpart, translated into action by the gung-ho Shaftoe and his forces. Fast-forward to the present, where Waterhouse's crypto-hacker grandson, Randy, is attempting to create a "data haven" in Southeast Asia - a place where encrypted data can be stored and exchanged free of repression and scrutiny. As governments and multinationals attack the endeavour, Randy joins forces with Shaftoe's tough-as-nails granddaughter, Amy, to secretly salvage a sunken Nazi submarine that holds the key to keeping the dream of a data haven afloat. But soon their scheme brings to light a massive conspiracy with its roots in Detachment 2702 linked to an unbreakable Nazi code called Arethusa. And it will represent the path to unimaginable riches and a future of personal and digital liberty...or to universal totalitarianism reborn.