Puzzle Script (Research in varieties and methods of encryption of letters)

Keeping governmental secrets in official letters is one of the important issues of governments in all periods and its importance increases every day so that scientists try to find new methods for encoding and decoding of information. Nowadays, in mathematics and computer science a number of fields and trends have been created for encryption. On the basis of sources and documents, the history of this practice goes back to Greek civilization. Some groups of people like criminals, prisoners and professional beggars use coded languages which linguists call them Argo. There is almost no scientific research about history and types of puzzle language and script in Persian literature, and even there is no entry for this issue in Persian encyclopedias. The main reasons of this are that, on the one hand, there are not enough sources and references about this issue and, on the other, the rules of such knowledge were not taught to people in fear of revealing the secrets. This article introduces not only the methods of encryption in Islamic culture but also encoding fonts, inks for invisible writing and the terminology of this science whose secrets have been hidden