What do you call the method of encryption that uses two different keys for encoding and decoding?

The method of encryption that uses two different keys for encoding and decoding is known as asymmetric encryption. In asymmetric encryption, one key is used for encryption (commonly referred to as the public key), while a different, related key is used for decryption (referred to as the private key). This dual-key mechanism allows secure communication and authentication, as the public key can be shared widely without compromising the security of the private key.

Asymmetric encryption is particularly advantageous for scenarios such as secure email transmission and digital signatures, where it is essential to verify the authenticity of the sender and ensure that only the intended recipient can decrypt the message.

In contrast, symmetric encryption utilizes the same key for both encryption and decryption, which means that anyone who has access to the key can decrypt the data. Hashing is a different process that generates a fixed-size output (called a hash) from input data, primarily used for data integrity verification rather than encryption. Stream ciphering is a type of symmetric encryption that encrypts data one bit or byte at a time, rather than in blocks.

Understanding these distinctions emphasizes the unique characteristics and purposes of asymmetric encryption, reinforcing why it is vital in modern cryptographic systems.