While the novel incorporates actual historical elements and real-world cryptography concepts, the main narrative is fictional, though it's meticulously researched to maintain historical accuracy in its World War II portions.

No, while the book contains detailed discussions of cryptography and mathematics, Stephenson crafts the narrative to be accessible to general readers while providing deeper layers for those with technical knowledge.

The storylines are connected through family lineages, shared locations, and the central mystery of the Japanese gold, with modern characters often discovering and building upon the actions of their World War II counterparts.