Cryptography is an essential practice required for secure communication between two parties. It preserves the confidentiality, integrity, availability, and authenticity of information thereby enhances the security of the data processing system and the information flow within an organization. Symmetric and asymmetric key cryptography are used for encryption and decryption of a message. Symmetric key cryptography is the most commonly used cryptography as it is fast and feasible for use in decrypting bulk messages and requires less computer resources. Chosen-plaintext attacks have been proposed for symmetric key cryptography as it uses single secret key to encrypt different messages. This paper introduces a novel symmetric key cryptography, where multiple random secret keys can be used to encrypt different messages, which is insecure under cipher text-only attacks, a weaker form of attack than chosen-plaintext attacks.

Symmetric cryptography Chosen plaintext attacks Random secret key Block cipher.