Abstract: In this paper, we principally introduce a new class of unconditionally secure authentication codes, called linear authentication codes(or linear A-codes)from free modules. We then derive an upper bound on the size of source space when other parameters of the system, that is, the sizes of the key space and authenticator space, and the deception probability are fixed. We give constructions that are asymptotically close to the bound and show applications of these codes in constructing distributed authentication systems. We realize the generalization of linear authentication codes from vector space over field to free modules over ring.
DOI: *As the DOI is a unique identifier, it is already available in the pdf version. **The DOI link will be activated in the first midst of January 2026.