Canonicalization Failures as a Recurring Vulnerability Class: Representation Divergence in Cryptographic Systems and Its Avoidance

Abstract

Cryptographic systems operate on bytes but mean semantic objects. The translation between the two is rarely unique. Where this uniqueness is not enforced, an attack surface opens up as soon as a hash, a signature, replay protection, or consensus identity depends on the representation. The same class of failure has been discovered independently and named locally across many ecosystems, as transaction malleability, non-deterministic value encoding, message malleability, or hash chain malleability, without its common root being tracked as a cross-ecosystem grid. This work organizes the scattered findings systematically: it shows that they are instances of one violated uniqueness condition, along two basic directions: multiple valid codes for one object (object-side multiple representation) or one code for multiple objects (code-side semantic collapse). The contribution is explicitly not the discovery of the phenomenon, but is threefold: the systematization by representation mechanism rather than by affected system, the bridge between classical canonicalization security and a representation- and computability-theoretic foundation, and the translation into an applicable review procedure (a canonicalization obligation with a sequence of review steps, a field-type classification, and an operational boundary model) with which the risk can be recognized preventively. We substantiate the class with worked-out cases, delimit it against incidents that are not representation problems, and deliberately keep the claims to what is demonstrable: enforced uniqueness can reduce the exploitability of a failure class, but it neither replaces further protective measures or makes any statement about cryptographic security in the narrower sense