Bitcoin has a cryptographic security feature to ensure that only the owner of a Bitcoin can spend it. The idea is that the owner generates two numbers—a private key that is secret and a public key that is published. The public key can be easily generated from the private key, but not vice versa. A signature can be used to verify that the owner holds the private key, without revealing the private key, using a technique known as an elliptic curve signature scheme. In this way, the receiver can verify that the owner possesses the private key and therefore has the right to spend the Bitcoin. View More