Topic
What is a public key?
Last reviewed:
- Quick fact 1
A public key is derived from the private key and is used to check that a transaction was signed by its owner.
Source: ethereum.org: Accounts
- Quick fact 2
The public key is used to verify transactions; the private key must stay secret.
Source: SEC Investor Bulletin: Crypto asset custody basics for retail investors (Dec 12, 2025)
- Quick fact 3
Addresses are made from public keys.
Source: ethereum.org: Accounts
The short lesson
Crypto uses key pairs. Each pair has a private key and a public key. They are linked by math.
- The private key is the secret. It signs transactions. Whoever has it controls the funds.
- The public key is made from the private key. It is safe to share. It lets anyone check that a signature really came from the matching private key.
The math only works one way. You can get the public key from the private key, but not the other way around.
Your wallet address is usually a shorter code made from your public key. That is what you give people when they send you crypto.
A simple picture: the address is like a mail slot, and the public key lets anyone check the seal on a letter. The private key is the only key that opens the box. Share the slot. Never share the key.
Related terms
Go deeper in Lesson 2: What a key is
Common questions
Is it safe to share my public key?
Yes. It cannot be used to work out your private key. Your address is what you usually share.
Is a public key the same as an address?
Not exactly. The address is usually made from the public key and is often shorter.
Can someone steal crypto with my public key?
No. They would need the private key or the seed phrase.
Where is my public key?
Your wallet manages it. You usually only need your address.