| Abstract [eng] |
Traditional models of electronic money, usually used for electronic payment systems are not adap- ted for small amounts of high-volume transactions. When the product is very low value, such as music, art, transport tickets, traditional schemes are far from ideal. Payments must be made very quickly, wi- thout requiring significant system resources. As we know the system resources cost money, and some low-value goods would become cheaper than the transaction costs. In this work i present the electronic money model based on the conceptual WebCoin electronic payment scheme. Model is extended by using a fully hierarchical proxy signature, Schnorr signature scheme and some small changes in the WebCoin scheme. Closed circuit of bank, customers and vendors is extended to fully hierarchical tree of banks. Blind signature from fully hieararchical electronic signature scheme is substituted with a classic Shnorr electronic signature scheme. Instead of two denominations of coins used by the WebCoin scheme, I introduce an additional denomination. In this way, I improve a system of micro amounts to medium-sized payments. Medium amount payments in this work are such that the transaction amount does not exceed 100 LTL, but other interpretations are possible. The system is prepared to be used with unlimited amounts, but in offline mode it is more difficult to prevent duplication or counterfeiting of money. Medium amount payments are simply not worth the risk. Analytical part of this work introduces different electronic money schemes and types of signatures, and review their properties. Methodological section presents models and schemes that are used in this work. It also will present theorems showing properties of schemes. Research part will describe the creation of functioning model and code of the package in which the model is realized. |
