Search key, WIF, mnemonic across 18 chains CtrlK

Fork-Split Replay Nonce

Recover a key reused across the 2017 BTC/BCH fork: enter a legacy address to fetch its BTC signatures automatically, then add the matching BCH transaction — a shared nonce (same r) reveals the private key.

Enter the legacy address: its BTC (legacy sighash) and BCH (BIP143+FORKID) spending signatures — r, s and z — are fetched automatically. If the ECDSA nonce was reused across the fork (same r) the private key is recovered.

Transactions to fetch per chain: newest for the address (a single TXID fetches just that one transaction).

Balance0 BTC

Received0 BTC

TX0

Optional — add a specific BTC/BCH transaction by hand (merged with the automatic scan)

One per line: rawTxHex | vin (BTC), rawTxHex | vin | amountSats (BCH), or z=… r=… s=… (merged with the scan above)

Instructions:
1. Enter a legacy Bitcoin address — its BTC (legacy sighash) and BCH (BIP143+FORKID) spending signatures are fetched automatically.
2. BTC and BCH sign the same spend with different sighashes, so a reused nonce produces the same r over two different messages z.
3. When a BTC and a BCH signature share r, the private key is recovered: d = (s1·k - z1)/r (mod n).
4. Optional: paste a specific BTC/BCH transaction in the box above to merge it with the automatic scan.

Educational tool — runs 100% in your browser. After the 2017 Bitcoin Cash fork the same key controlled coins at the same legacy address on both chains, but BTC and BCH sign with different sighashes (legacy vs BIP143+FORKID, hashtype 0x41). A wallet that reused its ECDSA nonce k across the two chains produced two signatures with the same r — enough to recover the key via d = (s1·k − z1)/r. Only analyze transactions you are authorized to test.