Private key
Private key: A private key is a secret number that proves you own the crypto at a blockchain address and lets you sign transactions to move it. Anyone who has your private key controls those funds, which is why it must never be shared, typed into a website or stored where others can reach it.
How a private key works
Your wallet generates a private key, then mathematically derives a public key and an address from it. The address is safe to share so people can send you crypto. The private key stays secret and creates a digital signature each time you send, which the network can check without ever seeing the key itself.
Private key vs seed phrase
Most modern wallets show you a seed phrase rather than a raw private key. The seed phrase is a human readable backup that can regenerate every private key in the wallet. Protecting the seed phrase therefore protects all of your keys at once.
Who holds your private key?
On an exchange, the exchange holds the keys and you hold an account (custodial). In a self-custody wallet such as a hardware wallet, you hold them (non-custodial). Neither is right for everyone, but you should always know which one you are using and what happens if a password, device or company disappears.
Simple habits that keep keys safe
- Never enter a private key or seed phrase into a website, form or chat. Genuine support teams never ask for one.
- Use a hardware wallet for larger long-term holdings.
- Keep offline backups in more than one secure location, and plan how family could access them.
Frequently asked questions
Can a private key be recovered if I lose it?
Only from your backup, usually the seed phrase. There is no company or password reset that can restore a lost self-custody key.
Is my wallet address the same as my private key?
No. Your address is public and safe to share. Your private key is secret and controls the funds.
Does an exchange account have a private key?
Yes, but the exchange holds it for you. You access your balance with a login rather than with the key itself.