<p>The problem of assessing the stability of cryptographic transformations in modern cryptography, which is usually implemented using an axiomatic or proof-based approach, is considered. Since quantum computing model changes the complexity of certain computational problems, (for example, integer factorization problems), cryptography considers algorithm classes that remain stable in the quantum computing model, i.e., the so-called “post-quantum cryptographic algorithms.” A generalization of this problem statement is the study of computational models containing cryptoanalysis algorithms, the best of which has exponential complexity or one close to it. The generalization of the problem of the existence of cryptosystems that are secure in the post-quantum world, namely, cryptosystems that are secure in certain computational models, as well as the practical application possibility of such models, are considered. The main result of the article is the creation of the universal computational model that generalizes a whole class of promising computational models, including the quantum one, and the construction of a cryptosystem that is stable within such a computational model.</p>