Post-quantum key encapsulation mechanism for preserving confidentiality of digitally transmitted message and method thereof

Abstract

The present invention relates to an improved post-quantum cryptographic system for preserving confidentiality by the sender of an electronic or digital message 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 public-private key pairs which sources from the KAZ-KEM Problem, whilst a trapdoor associated thereof are random elements from a public list. The cryptographic module (202) is configured for digitally encapsulating a 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 secret parameter and decapsulating a secret parameter and decrypting an electronic or digital message symmetrically by utilizing a symmetric decryption key derived via a key derivation function from the secret parameter, where the key encapsulation mechanism sources from the KAZ-KEM Problem, wherein the key encapsulation mechanism employs a key derivation function for generating a secret key from the secret parameter.