HD Wallet Key Tree: 2D BIP-32 Derivation Flow

Hierarchical-deterministic (HD) wallets derive an unlimited tree of key pairs from one master seed using BIP-32: each child key is the parent key plus an HMAC-SHA512 output, reduced modulo the curve order. This simulator computes that derivation for real, in the browser, with actual crypto.subtle HMAC-SHA512 calls and secp256k1-order modular arithmetic, and renders it as a pannable/zoomable 2D flowchart rather than a 3D scene: a top-down key tree, a live HMAC data-flow pipeline diagram for the selected node, and a log-scale brute-force chart that all update from the same computation. Build out branches with normal or hardened derivation, then "leak" a selected child's private key to watch the real consequence play out: on a normal path the leak lets an attacker reconstruct the parent key — and everything below it — from public data alone, while a hardened path keeps the damage contained to the single leaked leaf.