Public & Private Key
The cryptographic key pair that enables secure ownership and transfer of cryptocurrency on a blockchain.
What is Public/Private Key?
In cryptocurrency, a public and private key are a mathematically linked pair of cryptographic keys that form the foundation of digital asset ownership and transaction authorization. The private key is a randomly generated secret number (typically 256 bits) that proves ownership of funds and is used to sign transactions; whoever controls the private key controls the associated funds. The public key is derived from the private key using elliptic curve cryptography (ECDSA) and can be freely shared — it is used to verify that a transaction was signed by the corresponding private key. The wallet address users share to receive funds is itself derived from the public key through additional hashing. This asymmetric cryptography ensures that anyone can verify a valid transaction without learning the private key, while only the key holder can authorize spending.
Example
When a user sends Bitcoin, their wallet uses the private key to generate a digital signature unique to that transaction. Other nodes on the network use the sender's public key to verify the signature is valid without ever seeing the private key. If the private key is lost or stolen, the associated funds are permanently inaccessible or at risk — there is no password recovery.