P2PKH
Pay to Public Key Hash
The legacy Bitcoin address type beginning with 1, which locks funds to the hash of a public key rather than the key itself. An unspent P2PKH output does not reveal its public key.
Related terms
Whether an address's full public key is visible on-chain. Exposure matters because quantum risk to a wallet begins only once the public key is published — before that, an attacker sees just a hash.
A Bitcoin upgrade that moves signature data outside the transaction body, enabling lower fees and address types beginning with bc1q. From a quantum standpoint SegWit behaves like P2PKH — the public key appears on first spend.
A Bitcoin upgrade introducing bc1p addresses and Schnorr signatures. Taproot key-path spends place a public key in the output, so a funded Taproot address exposes a key earlier than a comparable P2PKH address.
The earliest Bitcoin output type, which places the raw public key directly in the script. P2PK outputs expose their public key from the moment they are funded, making them the most quantum-exposed coins on the network.