Glossary

Public Key

16/04/2026

A public key is the publicly shareable component of an asymmetric cryptographic key pair. Its counterpart is the private key, which must remain secret. Together, they enable secure, trustless ownership of cryptocurrency.

How public keys are generated

In cryptocurrency, public keys are derived from private keys using elliptic curve cryptography (ECC) — specifically the secp256k1 curve in Bitcoin and most PoW coins. The derivation is a one-way mathematical operation: it is computationally infeasible to reverse-engineer the private key from the public key.

Private key  →  (ECC multiplication)  →  Public key  →  (hashing)  →  Address

Public key vs. address

A wallet address is not the same as the public key — it is derived from it:

  1. The public key is hashed (using SHA-256 and RIPEMD-160 in Bitcoin).
  2. A checksum and version byte are added.
  3. The result is encoded (Base58Check or Bech32) to produce the address.

This extra step adds a layer of security: even if elliptic curve cryptography were ever broken, the hash layer would provide additional protection.

What you can do with a public key / address

  • Receive funds — share your address with anyone who wants to send you cryptocurrency.
  • Verify signatures — anyone can use a public key to verify that a message or transaction was signed by the corresponding private key holder.

You cannot spend funds with a public key alone. Spending requires a valid signature from the private key.

See also

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