P2PK
Pay To Pubkey
P2PK (Pay To Pubkey) is a script pattern that locks an output to a public key.
It is a simpler version of the more-commonly used P2PKH locking script.
How does P2PK work?
A P2PK lock just contains a public key and a CHECKSIG opcode:
 scriptPubKey
|
4104ae1a62fe09c5f51b13905f07f06b99a2f7159b2225f374cd378d71302fa28414e7aab37397f554a7df5f142c21c1b7303b8a0626f1baded5c72a704f7e6cd84cac |
04ae1a62fe09c5f51b13905f07f06b99a2f7159b2225f374cd378d71302fa28414e7aab37397f554a7df5f142c21c1b7303b8a0626f1baded5c72a704f7e6cd84c OP_CHECKSIG
|
P2PK |
|---|---|---|---|
| hex | opcodes | inline | stack |
To unlock it you just need to provide a valid signature:
 scriptSig
|
4730440220576497b7e6f9b553c0aba0d8929432550e092db9c130aae37b84b545e7f4a36c022066cb982ed80608372c139d7bb9af335423d5280350fe3e06bd510e695480914f01 |
30440220576497b7e6f9b553c0aba0d8929432550e092db9c130aae37b84b545e7f4a36c022066cb982ed80608372c139d7bb9af335423d5280350fe3e06bd510e695480914f01
|
|
|---|---|---|---|
| hex | opcodes | inline | stack |
When the script runs, the CHECKSIG opcode compares the signature against the public key, and pushes a 1 on to the stack if it is valid.
Where can you find P2PK scripts?
Despite being the simplest script for locking bitcoins to someone’s public key, P2PK is not used as much as the similar (yet more complex) P2PKH script.
You’ll most commonly find P2PK in coinbase transactions in the earlier blocks in the blockchain. This is because the original Bitcoin Core miner would use P2PK for the block reward when constructing a candidate block:1
Here are some examples of transactions using P2PK:
4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b- Coinbase transaction in the genesis block. (3rd January 2009)f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16- The first ever bitcoin transaction from Satoshi to Hal Finney actually used P2PK (Block 170, 12th January 2009)
Why did Satoshi use P2PK in the Bitcoin Core miner?
Not sure. You’ll have to ask her/him.
I think P2PKH was used as a convenient way for people to make transactions, as it allowed you to use addresses instead of passing around your public key (which is longer). However, the miner does not need the convenience of addresses, so P2PK made for a simpler choice.
Why don’t we use P2PK more often?
Because Satoshi designed P2PKH so that we can send each other shorter addresses instead of full public keys.
See: Why do we have P2PKH as well as P2PK?