Find which of your phrases still holds coins (offline UTXO set)

You have text you wrote yourself (old notes, a diary, a password list) and suspect one sentence in it was a brainwallet. Checking every candidate on a block explorer leaks every guess, and is slow. Instead, take a copy of the whole UTXO set from your own node and test the candidates against it offline.

1. On your node (Bitcoin Core 25 or newer), write the UTXO set to a file. This is public chain data, no keys:

    bitcoin-cli dumptxoutset /path/utxo.dat
   

   Or use rpc, which needs --allow-unlisted because the call writes a file. The slow-method default timeout is 3600 s; use --timeout to change it:

    rpc --allow-unlisted --auth-file ~/.bitcoin/.cookie http://127.0.0.1:8332 dumptxoutset '["/path/utxo.dat"]'
   

   Either way the file is written on the node host. Copy it to wherever utxo-set runs. If rpc reports status timeout, the node is still writing the file, so wait for it to finish.

   Both file layouts are read: Core 25-27 (no header magic) and Core 28+ (utxo magic, network magic, version). The format is detected from the first bytes; the network comes from the Core 28+ header, and addresses on stdin are matched by their scriptPubKey, so you do not need --chain.

2. Ask whether particular addresses are funded (utxo-set): one JSON line each, with value_sat (the sum of every unspent output paying exactly that script) and outputs.

   utxo-set --dump /in/utxo.dat < /in/addresses.txt

3. Search your text for a funded brainwallet (wallet-finder). Every line, every sentence and every run of 1 to 6 words becomes a candidate; each candidate's sha256 key gives the five address shapes (p2pkh, p2pkh-uncompressed, p2sh-p2wpkh, p2wpkh, p2tr), and each is looked up in the set. A hit prints the phrase, scheme, address and balance. No key is printed and nothing is signed. The phrase itself is printed, so send stdout to a private file (as below), not to a terminal log or an agent; the count of hits goes to stderr. Both tools run on the host for now, not in the sealed image (neither opens a network connection). Turn a hit into a key inside the sealed container with phrase-to-key (see input-brainwallet.md).

   wallet-finder --dump /in/utxo.dat < /in/notes.txt > /secrets/hits.jsonl

   Exit 0 means at least one hit, 1 means none (like grep). More candidates: --rules case,swap,typo,digit (the pw-candidates rules) and a wider --window. WarpWallet: --scheme warpwallet --salt EMAIL (scrypt: far slower per candidate, measured below). Hits print in the dump's network encoding (--chain overrides).

Measured (sh scripts/utxo-bench.sh, synthetic Core-25 dump, Intel Xeon 8 threads, Linux x86_64, at 751299a):

• load: a 20,000,000-coin dump in 9.1 seconds (2.2M coins/s), one thread (box load and page cache move this 5.8-20.8 s);
• memory: peak RSS of 0.99 GB, that is 48 bytes per distinct script plus the bloom filter;
• bloom: over 1,000,000 never-funded queries the bloom filter passed 0.31%, and the exact set reported 0 funded;
• wallet-finder, one thread: 20380 sha256 candidates/s, five addresses each;
• WarpWallet: 200 candidates in 118.8 seconds.

Scale to mainnet is not measured here: memory grows with the number of distinct funded scripts, not with chain size.

How the set works: every funded scriptPubKey is held in RAM, sorted, with its summed value; a bloom filter in front answers most misses without touching the sorted array, and every bloom "maybe" is confirmed by an exact binary search, so a bloom false positive is never reported as funded. Scripts other than the five standard templates (P2PK, multisig, ...) are keyed by their SHA-256. Measured size, speed and bloom false-positive rate are in docs/CLAIMS.md (utxo-* claims); the test that a known-funded address is found and a never-funded one is not runs against a dump written by real Bitcoin Core 25.2 (scripts/e2e.d/utxo-real.sh).

NOT BUILT: reading the node's chainstate LevelDB directly (use dumptxoutset), non-Bitcoin dumps other than those Core writes, and keeping the loaded set between runs (each run re-reads the dump).