Hash is the unique code on every block in the blockchain, like a fingerprint. This method of cryptography does not use any keys. Instead, it utilizes cipher, the algorithm to encrypt and decrypt data to generate hash values from plain text. The blockchain utilizes only the asymmetric and hash function method.

Asymmetric Encryption and Cryptocurrencies Cryptocurrencies stay secure by relying on modern asymmetric encryption methods and the secure nature of transactions on a blockchain. Cryptocurrency holders use private keys to verify that they are owners of their cryptocurrency.

Secret key encryption, also known as symmetric encryption, uses a single key to encrypt and decrypt data. This type of encryption is symmetric because the same key is used to encrypt plaintext into ciphertext and decrypt that ciphertext back into plaintext.