NADO Cryptography Using One-way Functions is a symmetric cryptography for encrypting and decrypting information. The NADO process introduces some novel concepts and methods to cryptography: (1) The notion of a key generator is presented that eliminates the dependence of the cryptographic security on a single, static cryptography key. (2) A key generator updating method built with one-way functions exhibiting the avalanche effect that generates an unpredictable sequence of keys as the encryption or decryption algorithm executes; (3) An sequence of unpredictable permutations that diffuse the informations across the whole block. (4) An sequence of unpredictable permutations that act as substitution boxes. (4) The use of key generator updating and one-way functions that exploit the avalanche effect to update the permutations in (3) and (4). NADO using one-way functions can be implemented efficiently in hardware or in software.