Public-Key Cryptography
A system using a paired public and private key so anyone can verify a signature only the owner could make.
Also called asymmetric cryptography, it uses two keys instead of one shared secret. The private key stays hidden and signs; the public key is shared and verifies. Crucially, you can't derive the private key from the public one.
This solves a problem older systems couldn't: proving identity to strangers without first exchanging a secret. Every crypto transaction works this way. You sign with your private key, and the whole network can confirm the signature against your public key — no trust required.
Related terms
The secret number that proves ownership of crypto and authorizes spending it; whoever holds it controls the funds.
Public KeyA key derived from your private key that others use to verify your signatures and that forms your address.
Digital SignatureA cryptographic proof that a specific keyholder authorized a message, and that it hasn't been altered since.
CryptographyThe math of scrambling and verifying information so only intended parties can read or trust it.