12_History — History — how the field got its habits

Level: reference · for context

Cryptography's rules are scar tissue. Kerckhoffs's principle, published algorithms, public competitions, and deep suspicion of anything unexamined all come from specific, documented failures — and the politics is not a side story: export controls, backdoor standards and legal pressure have shaped which algorithms you are running right now.

Enigma, DES and its deliberately short key, the Crypto Wars and the Clipper chip, Dual_EC_DRBG, and the AES and SHA-3 competitions that made "open contest" the default way a standard gets chosen.

The pages

#	Page	The question it answers	Status
1	Why designs are public	What did the field learn the hard way, and from what?	planned

Every page above is a plan until its row says written; see ROADMAP.md.

The through-line

Every rule in chapter 1 is somebody's post-mortem. Knowing whose makes the rule stick.