Applying anti-trust policies to increase trust in a versatile e-money system

Abstract

Due to business relationships, alliances, trust, and distribution of liability, distribution of power is an important issue in financial systems. At the same time as the security of the scheme is strengthened by this decentralization, the perception of the security is also strengthened, which is important from a business point of view. Furthermore, apart from increasing the security, client trust and availability of the system, distribution of power can also increase its functionality, as we demonstrate. We suggest an anti-trust mechanism, namely, a method for distribution of the centralized parties into many modules (potentially controlled by different entities), and apply it to a versatile electronic-money system. The method diffuses a task into distributed modules using recent cryptographic technology; doing so, it achieves increased security, privacy, availability and functionality without introducing any noticeable disadvantage. It uses Magic Ink Signatures [29], which are blind signatures that are distributedly generated using a threshold of signers, and where signatures can always be unblinded using (perhaps another) threshold of signers as well. Furthermore, we combine this with recent proactive technology, which enables a stronger adversarial setting. We also suggest techniques for reorganization of data stored and used by various functions, employing secure repository. The result is an electronic money system that allows user anonymity and its revocation (a notion recently advocated by some works so as to prevent potential criminal actions.) The control over revoking anonymity is given to distributed modules that control a hidden alarm channel. As part of the task diffusion we find ways to simplify and reduce the overall complexity of the system. The revocation ability and distribution of the trust are efficient and allow a large degree of versatility in the functionality of the system (change mechanisms, numerous financial instruments: cash, charge, check, micro-payments, etc.).