Add Great Wall — Tacit-knowledge seed derivation by fractal recall

[Yuri-SVB]

Summary

This PR submits a new Draft BIP: Great Wall, a procedure for deriving a BIP-0032 master seed from a secret that exists only in the user's memory.

Instead of recording a BIP-0039 mnemonic, the user memorizes a sequence of locations on deterministically rendered Burning Ship fractals. The recalled locations are decoded by a binary bisection algorithm into raw entropy, which is then re-encoded as a BIP-0039 mnemonic and stretched into a seed exactly as in BIP-0039 — so all derived keys and addresses are identical to those a BIP-0039 wallet would produce from the same entropy.

The scheme is built around Tacit Knowledge-Based Authentication (TKBA): the secret is held as non-verbalizable procedural memory, and its deployment is gated by a tunable memory-hard KDF, providing coercion-resistance without any physical backup artifact. It is forward- and backward-compatible with BIP-0039 and composes with Formosa (BIP-0450).

Process notes

• Submitted as an unnumbered bip.mediawiki with BIP: ? and Assigned: ? in the preamble.
• No number self-assigned and no README table entry added — left for a BIP Editor to assign and publish, following the same path Formosa (BIP-0450) took.
• Layer: Applications · Type: Specification · Status: Draft · License: BSD-2-Clause · Requires: 32, 39

Contents

• Specification: deterministic I4F60 fixed-point arithmetic; the binary bisection algorithm and the regular binary area tree it induces (cuts alternate along the largest dimension; weighted-median placement + contraction yielding a discarded area / checksum-like effect); the app-canonical fractal (fixed baseline perturbation p excluding the degenerate tail of the mathematics-canonical Burning Ship); the KDF-perturbed stage-2 fractal; sizing; recall-to-seed pipeline; computational gating / RSW time-lock; optional inheritance protocol.
• Rationale, Backwards Compatibility, Security Considerations, and Reference Implementation sections.

Reference implementation and documentation: https://github.com/Yuri-SVB/Great-Wallet

Checklist

• BIP Editor assigns a number and renames bip.mediawiki accordingly
• README.mediawiki table entry added on publication
• Discussion: link updated to the bitcoindev mailing-list thread (if/when available)

[danielabrozzoni]

Hey! BIP3 explicitly states that new BIPs should be discussed on the mailing list first:

bips/bip-0003.md

Lines 485 to 487 in 6deafd0

	* The idea has been previously proposed to the Bitcoin Development Mailing List and discussed there
	* The described idea is on-topic for the repository
	* A draft of the BIP by one of the authors has been previously discussed on the Bitcoin Development Mailing List

I can't find any thread on the mailing list, so I suggest you post this there before opening a BIP PR :)

[danielabrozzoni]

This should link to the discussion thread on the ML, not to your own repository (which, as far as I can see, doesn't even have issues/PRs where someone discussed the idea...)

[jonatack]

Thank you for your proposal, but it appears to have been opened here prematurely? See the README and BIP 3 for the process (thanks!)