eTRON for Ubiquitous Security

With the advent of ubiquitous computing technologies, the impact of computers in our society is bigger than ever. As a result, the security for computing systems is becoming more and more important. We believe it is crucial to establish a concrete security basis suitable for ubiquitous computing so as to build a reliable ubiquitous computing systems.

Among all these security issues, Sakamura-Koshizuka laboratory has been working on transfer/distribution of values, like tickets, money, credentials, and many others. As our living depends intensely on economic activities, it is practically very important to safely handle such 'values' in computer systems.

In spite of this necessity, economic values are in general difficult to be handled on computers, since 'values' must not be able to be copied; otherwise, they are no longer valuable. Although current valuable objects often avoid copying by physical solutions (e.g. watermarking), such techniques cannot be applied for digital data for copy protection, and it is in general quite easy create an identical copy of the original.

In order to solve this problem, Sakamura-Koshizuka laboratory has been working on eTRON architecture, a platform designed to distribute digital data with 'values' (electronic entities) in computing systems. Overall eTRON architecture is as shown in Figure 1.

Figure 1. eTRON Architecture

eTRON architecture consists of a network and nodes in it. Each eTRON node is mutually authenticated and connected each other by a protocol named eTP (entity transfer protocol), thus possible to securely transfer valuable information.

eTP protocol provides a limited range of functionalities, while usual service API provides a set of generic functions. This is because eTP is designed to assure that the digital data behave as "electronic entities." For instance, eTP provides a functionality to move a digital entity from one eTRON node to another, but no copying functions are provided in eTP, as digital entities should no be able to be duplicated.

As illustrated so far, eTRON architecture provides a basis for handling values or rights in digital data, which used to be difficult to be handled on computers. This special characteristics can be achieved not by adding new functionalities, but by restricting the some functionalities against digital data.