Twenty-one open-source tools and experiments in cryptography and Bitcoin.
Physically drawn playing cards to a BIP39 seed, offline, in one self-contained HTML file. There is no random number generator anywhere in it — no Math.random, no crypto.getRandomValues, not even a clock reading — so the seed comes from your shuffled deck and nothing else. Eight draws of four cards carry 181 bits of entropy to extract 128, and that surplus is what absorbs an imperfect shuffle instead of passing it through to your seed. Printable draw sheet, verify-by-re-entry, a shuffle-quality check, and the BIP32 master fingerprint plus your first two receive addresses so you can confirm the seed against your wallet before funding it. Published test vectors, a full specification, and a SHA-256 to check before you run it.
Three offline, self-contained HTML files for turning physical entropy into a BIP39 seed: one six-sided die, one 52-card deck, or two matching decks. Basic writes just the words; Full also shows the first receive addresses and a SeedQR. No network requests, no browser RNG — entropy comes from your rolls or draws, with a reproducible hardened-extractor line you can cross-check yourself.