Simple definition
A public key is like your bank account number: safe to share so others can send you things. A private key is like your PIN and signature in one: it must stay secret.
How it works
- Wallet software makes the two keys together, linked by maths.
- Your public key is used to create your wallet address, which people use to send you assets.
- Your private key signs transactions to prove they come from you.
- Public keyLike an account numberCreates your wallet address. People use it to send you assets.Safe to share
- Private keyLike a PIN and signatureProves you approve a transaction. Your wallet keeps it for you.Never share
- Recovery phraseThe backup wordsCan restore your wallet. Anyone who has it can take everything in it.Keep offline
Everyday example
In real life
Think of a mailbox with a slot. Anyone can drop in a letter (public), but only the person with the key can open it and take letters out (private).
Benefits and why this matters
Why this matters
Almost every crypto loss comes down to a private key or recovery phrase falling into the wrong hands. This is the one idea worth learning first.
- Proves you approved something without sharing a password
- Works without a central company in the middle
- The same idea protects many online services
Risks and limitations
Things to watch out for
- Watch out: Never share your private key or recovery phrase with anyone, including "support" staff
- Watch out: Messages asking for it are scams
- Watch out: If it is lost, access is gone
Your beginner action
Try this
Learn this rule: never type your recovery phrase into a website or send it in a message. Write the rule on a note near your desk.