Transnational Consumer Law: Co-Regulation of B2C-E-Commerce

The nation states provide workable contract enforcement institutions for domestic commerce. Due to a lack of international cooperation the same does not hold true when it comes to cross-border situations. Thus, the institutional organization of international commerce is characterized by its reliance on private ordering or private legal services. Many believe that the emergence of a New Law Merchant can be observed in international commercial arbitration. This trend towards the privatization of commercial law, however, is believed to be limited to the sphere of corporate actors or merchants. When it comes to the protection of weaker contract parties like consumers, self-regulation is not held to be a viable option. In fact, consumers do shop increasingly across borders when engaging in e-commerce, often without noticing. The 1999 OECD Guidelines proposed to tackle the resulting consumer protection concerns by means of co-regulation. In this article, I intend to examine the potential role of private ordering and co-regulation in the area of cross-border consumer contracts. I start with a survey of the different mechanisms of private ordering, which have developed in e-commerce. This illustrates that electronic market places fulfil an essential role in bundling different means of private ordering into what I call transnational civil regimes for consumer protection. Finally, I aim at demonstrating how states, industry, and civil society actors can jointly contribute to the establishment of a civil constitution for such regimes

Security and Efficiency Analysis of the Hamming Distance Computation Protocol Based on Oblivious Transfer

open access articleBringer et al. proposed two cryptographic protocols for the computation of Hamming distance. Their first scheme uses Oblivious Transfer and provides security in the semi-honest model. The other scheme uses Committed Oblivious Transfer and is claimed to provide full security in the malicious case. The proposed protocols have direct implications to biometric authentication schemes between a prover and a verifier where the verifier has biometric data of the users in plain form. In this paper, we show that their protocol is not actually fully secure against malicious adversaries. More precisely, our attack breaks the soundness property of their protocol where a malicious user can compute a Hamming distance which is different from the actual value. For biometric authentication systems, this attack allows a malicious adversary to pass the authentication without knowledge of the honest user's input with at most $O(n)$ complexity instead of $O(2^n)$, where $n$ is the input length. We propose an enhanced version of their protocol where this attack is eliminated. The security of our modified protocol is proven using the simulation-based paradigm. Furthermore, as for efficiency concerns, the modified protocol utilizes Verifiable Oblivious Transfer which does not require the commitments to outputs which improves its efficiency significantly

Transnational Consumer Law: Co-Regulation of B2C-E-Commerce

The nation states provide workable contract enforcement institutions for domestic commerce. Due to a lack of international cooperation the same does not hold true when it comes to cross-border situations. Thus, the institutional organization of international commerce is characterized by its reliance on private ordering or private legal services. Many believe that the emergence of a New Law Merchant can be observed in international commercial arbitration. This trend towards the privatization of commercial law, however, is believed to be limited to the sphere of corporate actors or merchants. When it comes to the protection of weaker contract parties like consumers, self-regulation is not held to be a viable option. In fact, consumers do shop increasingly across borders when engaging in e-commerce, often without noticing. The 1999 OECD Guidelines proposed to tackle the resulting consumer protection concerns by means of co-regulation. In this article, I intend to examine the potential role of private ordering and co-regulation in the area of cross-border consumer contracts. I start with a survey of the different mechanisms of private ordering, which have developed in e-commerce. This illustrates that electronic market places fulfil an essential role in bundling different means of private ordering into what I call transnational civil regimes for consumer protection. Finally, I aim at demonstrating how states, industry, and civil society actors can jointly contribute to the establishment of a civil constitution for such regimes

Perfect Implementation

Privacy and trust aect our strategic thinking, yet they have not been precisely modeled in mechanism design. In settings of incomplete information, traditional implementations of a normal-form mechanism - by disregarding the players' privacy, or assuming trust in a mediator - may fail to reach the mechanism's objectives. We thus investigate implementations of a new type. We put forward the notion of a perfect implementation of a normal-form mechanism M: in essence, a concrete extensive-form mechanism exactly preserving all strategic properties of M, without relying on a trusted mediator or violating the privacy of the players. We prove that any normal-form mechanism can be perfectly implemented by a verifiable mediator using envelopes and an envelope-randomizing device (i.e., the same tools used for running fair lotteries or tallying secret votes). Differently from a trusted mediator, a veriable one only performs prescribed public actions, so that everyone can verify that he is acting properly, and that he never learns any information that should remain private

Enabling Privacy-preserving Auctions in Big Data

We study how to enable auctions in the big data context to solve many upcoming data-based decision problems in the near future. We consider the characteristics of the big data including, but not limited to, velocity, volume, variety, and veracity, and we believe any auction mechanism design in the future should take the following factors into consideration: 1) generality (variety); 2) efficiency and scalability (velocity and volume); 3) truthfulness and verifiability (veracity). In this paper, we propose a privacy-preserving construction for auction mechanism design in the big data, which prevents adversaries from learning unnecessary information except those implied in the valid output of the auction. More specifically, we considered one of the most general form of the auction (to deal with the variety), and greatly improved the the efficiency and scalability by approximating the NP-hard problems and avoiding the design based on garbled circuits (to deal with velocity and volume), and finally prevented stakeholders from lying to each other for their own benefit (to deal with the veracity). We achieve these by introducing a novel privacy-preserving winner determination algorithm and a novel payment mechanism. Additionally, we further employ a blind signature scheme as a building block to let bidders verify the authenticity of their payment reported by the auctioneer. The comparison with peer work shows that we improve the asymptotic performance of peer works' overhead from the exponential growth to a linear growth and from linear growth to a logarithmic growth, which greatly improves the scalability