What it is
A public key is a cryptographic code that is mathematically derived from a private key but cannot be used to deduce the private key itself. For Bitcoin, a public key is used to generate a public address, which is the string of characters people share to receive cryptocurrency. While the public key is openly shared, it does not reveal the private key, maintaining the security of the funds associated with that address.
Public keys are a core component of how Bitcoin transactions function and are often referenced in explanations of cryptographic security and wallet operations. When discussing sending or receiving Bitcoin, news articles or guides will refer to sharing a "Bitcoin address," which is the human-readable form derived from the public key. Readers need to understand that the public key and its derived address are for receiving funds, while the private key is for spending them.
Why it matters
Understanding public keys helps you grasp how Bitcoin addresses are generated and how to securely receive funds without compromising your private key. It's half of the cryptographic pair.
Reviewed under editorial standardsUpdated September 26, 2026Not investment advice