In the book is presented a new approach to understanding of the genetic code as well as chemical code (Periodic system of chemical elements). For a better understanding of genetic coding, it is proposed a hypothesis after that (under the conditions of allowed metaphoricity and modeling in biology) genetic code has to be understood, analogously to understanding in cryptology, as the unity of the three entities: the code, the cipher of the code and the key of the cipher. In this hierarchy the term (and notion) "genetic code" remains what has been from the beginning: a connection between four-letter alphabet (four Py-Pu nucleotides, in form of codons) and a twenty-letter alphabet (twenty amino acids); the cipher is a specific chemical complementarity in chemical properties of molecules in the form: similarity in dissimilarity versus dissimilarity in similarity and the key of cipher: the complementarity on the binary tree of the genetic code in the form: 0-15, 1-14, 2-13, ..., 6-9, 7-8.