Generating cryptographic checksums

Abstract

A method () of generating a cryptographic checksum for a message M(x) is provided. The method comprises pseudo-randomly selecting () at least two irreducible polynomials p(x). Each irreducible polynomial p(x) is selected based on a first cryptographic key from the set of irreducible polynomials of degree nover a Galois Field. The method further comprises calculating () a generator polynomial p(x) of degree n=formula (I) as a product of the N irreducible polynomials formula (II), and calculating () the cryptographic checksum as a first function g of a division of a second function of M(x), ƒ(M(x)), modulo p(x), i.e., g(ƒ(M(x)) mod p(x)). By replacing a standard checksum, such as a Cyclic Redundancy Check (CRC), with a cryptographic checksum, an efficient message authentication is provided. The proposed cryptographic checksum may be used for providing integrity assurance on the message, i.e., for detecting random and intentional message changes, with a known level of security. Further, a corresponding computer program, a corresponding computer program product, and a checksum generator for generating a cryptographic checksum, are provided.