Description: The method of defence of the inexpensive programs is offered by authorizing over the internet. Described the developed protocol, based on the use of electronic digital signature, and his programmatic realization. The analysis of firmness of method is conducted to the known types of attacks. The known methods of defence of software are considered от the illegal use and comparing of the offered method is conducted to them. It is shown that the offered method allows to protect a shareware, not losing efficiency of defence here.
Keywords: protocol, protecting from copying, software, shareware