This article examines the technical possibilities of electronic cash payment methods that do not use ledgers. This article is a paper by Yuko Tamura and 10 other researchers published in Financial Research Vol. 44 No. 3 (July 2025), providing detailed technical considerations on innovative payment methods that enable settlement through transmission and reception of electronic data resembling cash without intermediary service providers or ledgers.
This payment method is a means of settlement through transmission and reception of electronic data resembling cash, long studied as "electronic cash" in cryptographic research fields. Several demonstration experiments were conducted in the 1990s, but practical implementation was not achieved due to difficulties in ensuring usability at the technical standards of that time. However, considering technological advances and changes in social needs during this period, the research team conducted reorganization of electronic cash methods.
The core of the research is verification of practicality through actual device testing using smartphones. It demonstrates empirically that high-usability electronic cash systems can be provided at current technical standards. This results from complex contributions including improved processing capacity, communication technology development, cryptographic advances, and user interface improvements.
Two important functions are proposed as technical innovations. First, development of methods that enable division and aggregation of electronic cash into arbitrary amounts. This achieves flexibility similar to conventional physical cash in electronic cash. Second, proposal of methods that make it difficult to correlate electronic cash used by the same user. This is an extremely important function from a privacy protection perspective, preventing tracking of user transaction histories and behavior patterns.
Electronic cash characteristics include the ability to directly transfer value between users without requiring centralized ledgers or payment service providers. This is a fundamentally different approach from currently mainstream digital payment systems, potentially significantly reducing dependence on financial intermediaries. Benefits such as payment execution in offline environments and ensuring transaction anonymity are also expected.
However, the researchers clearly state that this article is purely technical consideration, excluding legal and institutional development, operational challenges, and feasibility for social implementation from consideration. Keywords include smartphone payments, digital payments, electronic cash, electronic money, and privacy protection, with future technological development in these fields expected.
The article concludes that electronic cash technology shows possibilities for practical implementation at current technical standards, while technical foundations for further usability improvement and privacy enhancement are being established.