HLS-Based Methodology for Fast Iterative Development Applied to Elliptic Curve Arithmetic

International audienceHigh-Level Synthesis (HLS) is used by hardware developers to achieve higher abstraction in circuit descriptions. In order to shorten the hardware development time via HLS, we present an adjustment of the Iterative and Incremental Design (IID) methodology, frequently used in software development. In particular, our methodology is relevant for the development of applications with unusual complexity: the method was applied here to the development of large modular arithmetic, commonly used for cryptography applications (e.g., Elliptic Curves). Rapid feedback on circuit characteristics is used to evaluate deep architectural changes in short time, greatly reducing the time-to-market with respect to hand-made designs. In addition, our approach is highly flexible, since the same generic high-level description can be used to produce an entire set of circuits, each with different area/performance trade-offs. Thanks to the proposed approach, any change to the initial specification (e.g., the curve used) is also very fast, while it may require a large effort in the case of hand-made designs

A trust-driven privacy architecture for vehicular ad-hoc networks

Vehicular Ad-Hoc NETworks (VANETs) are an emerging technology which aims to improve road safety by preventing and reducing traffic accidents. While VANETs offer a great variety of promising applications, such as, safety-related and infotainment applications, they remain a number of security and privacy related research challenges that must be addressed. A common approach to security issues widely adopted in VANETs is the use of Public Key Infrastructures (PKI) and digital certificates in order to enable authentication, authorization and confidentiality. These approaches usually rely on a large set of regional Certification Authorities (CAs). Despite the advantages of PKI-based approaches, there are two main problems that arise, i) the secure interoperability among the different and usually unknown- issuing CAs, and ii) the sole use of PKI in a VANET environment cannot prevent privacy related attacks, such as, linking a vehicle with an identifier, tracking vehicles ¿big brother scenario" and user profiling. Additionally, since vehicles in VANETs will be able to store great amounts of information including private information, unauthorized access to such information should be carefully considered. This thesis addresses authentication and interoperability issues in vehicular communications, considering an inter-regional scenario where mutual authentication between nodes is needed. To provide interoperability between vehicles and services among different domains, an Inter-domain Authentication System (AS) is proposed. The AS supplies vehicles with a trusted set of authentication credentials by implementing a near real-time certificate status service. The proposed AS also implements a mechanism to quantitatively evaluate the trust level of a CA, in order to decide on-the-y if an interoperability relationship can be created. This research work also contributes with a Privacy Enhancing Model (PEM) to deal with important privacy issues in VANETs. The PEM consists of two PKI-based privacy protocols: i) the Attribute-Based Privacy (ABP) protocol, and ii) the Anonymous Information Retrieval (AIR) protocol. The ABP introduces Attribute-Based Credentials (ABC) to provide conditional anonymity and minimal information disclosure, which overcome with the privacy issues related to linkability (linking a vehicle with an identifier) and vehicle tracking (big brother scenario). The AIR protocol addresses user profiling when querying Service Providers (SPs), by relying in a user collaboration privacy protocol based on query forgery and permutation; and assuming that neither participant nodes nor SPs could be completely trusted. Finally, the Trust Validation Model (TVM) is proposed. The TVM supports decision making by evaluating entities trust based on context information, in order to provide i) access control to driver and vehicle's private information, and ii) public information trust validation

Trusted Execution Development: Designing a Secure, High-Performance Remote Attestation Protocol

Intel Software Guard Extensions (SGX) are a Trusted Execution Environment (TEE) technology that allow programs to protect execution process and data from other processes on the platform. We propose a method to combine SGX attestation with Transport Layer Security (TLS). Doing so will combine guarantees about the program, runtime environment, and machine identity into a normal TLS handshake. We implemented a basic server using SGX/TLS and provide performance details and lessons learned during development

Centrally Banked Cryptocurrencies

Current cryptocurrencies, starting with Bitcoin, build a decentralized blockchain-based transaction ledger, maintained through proofs-of-work that also generate a monetary supply. Such decentralization has benefits, such as independence from national political control, but also significant limitations in terms of scalability and computational cost. We introduce RSCoin, a cryptocurrency framework in which central banks maintain complete control over the monetary supply, but rely on a distributed set of authorities, or mintettes, to prevent double-spending. While monetary policy is centralized, RSCoin still provides strong transparency and auditability guarantees. We demonstrate, both theoretically and experimentally, the benefits of a modest degree of centralization, such as the elimination of wasteful hashing and a scalable system for avoiding double-spending attacks.Comment: 15 pages, 4 figures, 2 tables in Proceedings of NDSS 201