Public key

What is Public key?

A public key is a cryptographic component of asymmetric encryption used extensively in blockchain systems to enable secure, transparent, and decentralized transactions. It is mathematically derived from a corresponding private key and serves as a visible identifier for receiving funds, verifying digital signatures, and participating in various blockchain-based activities. While the public key can be safely shared with others, the private key - used to generate it - must always be kept confidential.

In the context of cryptocurrencies, public keys are fundamental to wallet functionality. When a user generates a new wallet, a key pair is created: a private key and a public key. The public key is used to derive a blockchain address, which other users can send funds to. When a transaction is initiated from that address, the user proves ownership by signing the transaction with their private key. Network validators then use the public key to verify that the signature is valid, confirming that the transaction was authorized by the rightful owner.

Public keys are not only limited to payments. They are also used in smart contracts, non-fungible tokens (NFTs), and other cryptographic protocols to authenticate identities, manage access rights, and ensure the integrity of decentralized systems. Many blockchains compress or hash public keys into shorter wallet addresses to make them more user-friendly, especially for peer-to-peer interactions.

Importantly, although public keys are derived from private keys, it is computationally infeasible to reverse this process - meaning no one can uncover your private key just by knowing your public key. This asymmetric relationship forms the foundation of trustless systems, enabling secure asset transfers without intermediaries.

As blockchain adoption grows, public key infrastructure (PKI) is becoming increasingly essential for enabling cryptographically secure interactions across finance, identity management, and digital communications.