Zcash is a fork of Bitcoin with optional anonymity features. While transparent transactions are fully linkable, shielded transactions use zero-knowledge proofs to obscure the parties and amounts of the transactions. First, we observe various metrics regarding the usage of shielded addresses. Moreover, we show that most coins sent to shielded addresses are later sent back to transparent addresse...

In 2013, Baseri et al. proposed an untraceable off-line electronic cash scheme from the RSA cryptosystem. They used a method that injects the expiration date and the spenders identity onto the coin to prevent double spending. The authors claimed that the scheme provides the properties of anonymity, unforgeability, double spending detection, and date attachability. Unfortunately, we find that th...

We present the self-paced 3-class Graz brain-computer interface (BCI) which is based on the detection of sensorimotor electroencephalogram (EEG) rhythms induced by motor imagery. Self-paced operation means that the BCI is able to determine whether the ongoing brain activity is intended as control signal (intentional control) or not (non-control state). The presented system is able to automatica...

Donor funds are available for treatment of many diseases such as HIV. However, privacy constraints make it hard for donor organisations to verify that they have not sponsored the same patient twice — or sponsored a patient whose treatment was also sponsored by another donor. This paper presents a protocol based on digital cash that enables donor organisations to obtain a proof (in the form of a...

We propose a generic framework for the development of an off-line peer-to-peer electronic payment system with fixed-value electronic coins. The proposed scheme simulates the issuance, circulation and characteristics of conventional cash and satisfies important security, privacy and usability requirements, offering a comparative advantage over other existing solutions. We exploit the strong secu...

Many electronic cash systems have been proposed with the proliferation of the Internet and the activation of electronic commerce. E-cash enables the exchange of digital coins with value assured by the bank’s signature and with concealed user identity. In an electronic cash system, a user can withdraw coins from the bank and then spends each coin anonymously and unlinkably. In this paper, we des...

This paper aims to investigate the origins of ancient coins Japan (until 10th century CE), introduce characteristics their design and patterns, examine role in early Japanese culture public administration, while briefly introducing Chinese that served as inspiration. adopted numerous cultural practices during Asuka Nara periods (538–794 CE). Especially from second half 7th 8th CE, introduced va...