Post-quantum key agreement mechanism for preserving confidentiality of digitally transmitted secret and method thereof

Abstract

The present invention relates to an improved post-quantum cryptographic system for preserving confidentiality of an agreed secret parameter between a sender and recipient in a transaction over a data communication system between a sender and a recipient through a certifying authority. The post-quantum cryptographic system preferably comprises a cryptographic unit (100) comprising a memory (200) having a key generation module (201) and a cryptographic module (202) and a processor (300). The key generation module (201) is configured for generating private seeds having a minimum length of 128 bits either from a true random number generator or a pseudo random number generator and comprises an algorithm for generating partial agreed secret parameters and the agreed secret parameter which sources from the KAZ-KA Problem, whilst a trapdoor associated thereof are random elements from a public list. The cryptographic module (202) is configured for digitally generating a partial agreed secret parameter, the agreed secret parameter and encrypting an electronic or digital message with a corresponding symmetric cryptosystem by utilizing a symmetric encryption key derived via a key derivation function from the agreed secret parameter and decrypting an electronic or digital message symmetrically by utilizing a symmetric decryption key derived via a key derivation function from the agreed secret parameter generated from the partial agreed secret parameter exchanged beforehand between the sender and recipient, where the key agreement mechanism sources from the KAZ-KA Problem, wherein the key agreement mechanism employs a key derivation function for generating a secret key from the agreed secret parameter.