Pay to R-Puzzle Hash contract.

P2RPH scripts lock Bitcoin to a hash puzzle based on the R value of an ECDSA signature. The funds can be unlocked with knowledge of the corresponding K value (the ECDSA nonce), allowing the spending party to sign with any key pair.

Lock parameters

• :r_hash — 20-byte HASH160 of the R value (preferred)
• :r — raw R value binary (will be HASH160'd automatically)

Unlock parameters

• :privkey — a BSV.PrivateKey.t() (any key pair works)
• :k — the K value (ECDSA nonce) as a 32-byte binary
• :pubkey — the corresponding compressed public key binary

How it works

The locking script extracts the R value from a signature on the stack, hashes it, and compares against the committed hash. Two signatures are required: one with the known K value (proving knowledge of K), and a standard signature from any key pair.

Example

k = BSV.Contract.P2RPH.generate_k()
r = BSV.Contract.P2RPH.get_r(k)

# Lock
contract = P2RPH.lock(1000, %{r: r})

# Unlock (with any keypair)
contract = P2RPH.unlock(utxo, %{
  privkey: my_privkey,
  k: k,
  pubkey: my_pubkey_bin
})