By far the most important automated tool for network and communications security is encryption, but encryption itself needs security. As we know, many cryptosystems and cryptographic protocols are based their security on some computationally intractable mathematical problems. In this paper, we shall discuss some of the number-theoretic problems that are currently polynomially uncomputable and thus provide a good base for cryptography and network security.
Song Y. Yan, Glyn James, Gongyi Wu