We consider the problem of finding edges of a hidden weighted graph using a certain type of queries. Let G be a weighted graph with n vertices. In the most general setting, the n vertices are known and no other information about G is given. The problem is finding all edges of G and their weights using additive queries, where, for an additive query, one chooses a set of vertices and asks the sum...

Last time we introduced the notion of interactive proof systems which models computation as a result of interaction between two parties. We defined public/private coin protocols, and showed that the graph non-isomorphism problem admits an interactive proof using private coins, as well as one using public coins. Today we will continue our discussion of interactive proof systems. We will study th...

This set of notes explains the process that Prof. Jones used to develop the FSM for the lab. The lab simulates a vending machine mechanism for automatically identifying coins (dimes and quarters only), tracking the amount of money entered by the user, accepting or rejecting coins, and emitting a signal when a total of 35 cents has been accepted. In the lab, we will only drive a light with the “...

We provide a mechanism that uses two biased coins and implements any distribution on a finite set of elements, in such a way that even if the outcomes of one of the coins is determined by an adversary, the final distribution remains unchanged. We apply this result to show that every quitting game in which at least two players have at least two continue actions has an undiscounted ε-equilibrium,...

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...