Pay-to-PubKey-Hash (P2PKH): Definition and How Legacy Bitcoin Addresses Work
Pay-to-PubKey-Hash (P2PKH) is the original and most widely recognized Bitcoin transaction format. It locks Bitcoin to the hash of a public key, allowing only the owner of the corresponding private key to spend the funds. Legacy Bitcoin addresses that begin with "1" use the P2PKH format.
Pay-to-PubKey-Hash (P2PKH) Explained in Simple Terms
When someone sends Bitcoin, the coins are not sent directly to a person or even to a public key.
Instead, they are locked to a hash of the recipient's public key.
Later, when the recipient wants to spend those coins, they must prove ownership by providing:
the original public key
a valid digital signature created with the matching private key
If both pieces of information are correct, the Bitcoin network unlocks the funds and allows them to be spent.
This mechanism became the foundation of Bitcoin transactions and remained the standard format for many years.
How Pay-to-PubKey-Hash (P2PKH) Works
A P2PKH transaction follows a straightforward verification process.
The process works as follows:
Wallet Generates Keys
A private key and public key are created.Bitcoin Address Created
The public key is hashed to produce a legacy Bitcoin address.Funds Received
Bitcoin is sent to that address.Transaction Signed
When spending the funds, the wallet creates a digital signature using the private key.Network Verification
Bitcoin nodes verify that the signature matches the public key and that the public key matches the stored hash.
The spending condition can be summarized as:
Only the holder of the correct private key can satisfy these conditions.
Example of Pay-to-PubKey-Hash (P2PKH) in Practice
Alice generates a Bitcoin wallet that creates a legacy address beginning with 1.
Bob sends 0.5 BTC to that address.
The transaction output stores the hash of Alice's public key rather than the public key itself.
Later, when Alice spends the Bitcoin, her wallet provides:
the original public key
a digital signature proving ownership
Bitcoin nodes verify both pieces of information before accepting the transaction.
Why P2PKH Matters
P2PKH established the standard transaction model that Bitcoin used for many years.
It introduced a secure and efficient way to:
receive Bitcoin
verify ownership
protect private keys
prevent unauthorized spending
Although newer transaction formats have improved efficiency and privacy, P2PKH remains fully supported by the Bitcoin network.
P2PKH Address Format
P2PKH addresses are easy to recognize because they begin with:
1
Example:
1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa
These addresses are often referred to as legacy Bitcoin addresses because they were the original address format used by Bitcoin.
Many older wallets and exchanges still support them.
P2PKH vs SegWit
P2PKH
Characteristics include:
addresses begin with 1
uses legacy transaction format
higher transaction weight
generally higher fees
SegWit (P2WPKH)
Characteristics include:
addresses begin with bc1
separates witness data
lower transaction fees
improved scalability
fixes transaction malleability
SegWit was introduced to address several limitations of the legacy P2PKH format while maintaining compatibility with the Bitcoin network.
P2PKH vs Taproot
P2PKH
Designed primarily for standard single-signature payments.
Taproot (P2TR)
Introduces:
Schnorr Signatures
improved privacy
more efficient scripting
enhanced smart contract capabilities
While P2PKH remains functional, Taproot represents the latest evolution of Bitcoin transaction design.
Is P2PKH Still Used?
Yes.
Although many users have migrated to SegWit and Taproot addresses, P2PKH is still widely supported because of its excellent compatibility across wallets, exchanges, and payment services.
Legacy addresses continue to function exactly as they always have, and Bitcoin nodes fully validate P2PKH transactions alongside newer transaction formats.