Public Key

A public key is a cryptographic code that is mathematically derived from a private key and used to receive funds or verify digital signatures on a blockchain. It serves as the visible identifier of a wallet, enabling anyone to send assets to the corresponding address or confirm that a message or transaction was signed by the rightful owner.

In asymmetric cryptography, which underpins blockchain technology, the public key works together with the private key as part of a secure key pair. While the private key must remain secret, the public key can be openly shared without compromising security. This mechanism enables trustless transactions and secure identity verification across decentralized networks.

How Public Keys Work

1. Key Pair Generation - A wallet generates a private key, from which a public key is derived using elliptic curve cryptography (e.g. ECDSA).
2. Address Creation - The public key is hashed to generate a wallet address, which users can share to receive funds.
3. Transaction Verification - When a transaction is signed with a private key, network nodes use the public key to validate the signature.
4. Secure Communication - In broader cryptographic systems, public keys can be used to encrypt messages that only the private key holder can decrypt.
5. Open Sharing - Public keys are stored on-chain and visible to all participants, enabling decentralized transparency.

Key Features

• Derived from Private Key - Uniquely generated using one-way cryptographic functions.
• Safe to Share - Can be openly distributed without risk of asset loss.
• Foundation of Wallet Address - Used to create blockchain wallet addresses.
• Signature Verification - Enables confirmation that a transaction or message was signed by the rightful owner.
• Mathematical Pairing - Works only with its associated private key for authentication.

Benefits of Public Keys

• Transparency - Publicly viewable keys enhance auditability and traceability on-chain.
• Secure Identity - Provides a cryptographic identity layer for wallets, users, and contracts.
• Decentralized Verification - Eliminates the need for centralized authorities in validating actions.
• Interoperability - Compatible with wallet and contract standards across major blockchains.
• Trustless Interactions - Supports secure transactions without requiring direct trust between parties.

Use Cases of Public Keys

1. Receiving Funds - Shared as wallet addresses to accept cryptocurrencies like Bitcoin or ETH.
2. Signature Verification - Used by nodes to confirm that a transaction was signed by the correct private key.
3. Smart Contracts - Public keys are used to manage permissions, ownership, and role verification in contract logic.
4. Multi-Signature Wallets - Each signer contributes a public key to validate joint control over funds.
5. Web3 Authentication - Login systems use public keys to establish decentralized user identities.
6. Secure Messaging - In off-chain systems, public keys enable encrypted communication between peers.