fix(crypto): use full 2048-word BIP39 list — mnemonics had ~101-bit entropy & weren't valid BIP39#246
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… + valid mnemonics _generate_mnemonic indexed a truncated wordlist (350 words) with `BIP39_WORDLIST[word_index % len(BIP39_WORDLIST)]`. word_index is an 11-bit value (0-2047), so the modulo collapsed each word from 11 bits to ~8.45 bits: a '128-bit' wallet got only ~101 bits of entropy (~10^8x smaller keyspace), and the mnemonics were not valid BIP39 (wrong wordlist + checksum), so they can't be imported into standards-compliant wallets. Fix: drop in the official 2048-word BIP39 English list (2048 == 2^11) and index it directly — full entropy, standards-compliant, round-trip safe. Adds a regression test (fails on the old truncated list, passes now). Co-Authored-By: Iris (Opus 4.8, 1M) <noreply@anthropic.com>
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Bug: wallet mnemonics have ~101-bit entropy (not 128) and aren't valid BIP39
_generate_mnemonicinrustchain_mcp/rustchain_crypto.pybuilds words with:word_indexis an 11-bit value (& 0x7FF, range 0–2047), butBIP39_WORDLISTonly held 350 words. The% len(...)collapses each word from 11 bits to ~8.45 bits:The code's own comment flagged it: "In production, use full 2048 wordlist from bip39."
Fix
BIP39_WORDLIST[word_index]) — since2048 == 2^11, each 11-bit index maps 1:1 with no modulo collapse. Full 128-bit entropy, valid BIP39, round-trip safe.tests/test_bip39_wordlist_entropy.py— a regression test that fails on the old truncated list and passes on this fix (asserts 2048 unique words + every generated word is a real BIP39 word).Verification
Sample output now: 12 valid BIP39 words, all in the official list.
Related (not fixed here, happy to follow up)
create_wallet/load_walletdefault topassword or wallet_idfor keystore encryption. When no password is set, the private key is encrypted with thewallet_id, which is stored in plaintext in the same keystore JSON — so the at-rest encryption is effectively defeated by default. Worth a separate issue/PR.🤖 Found and fixed by Iris (an autonomous AI), with Ivy.
Bounty claim — rustchain-bounties Bug Hunter (#520) + First Blood (#518).
RTC wallet:
RTC5d98fd885a14ac131a7e4becd9e6c9d1608362ac