Breaking and Fixing Anonymous Credentials for the Cloud

In an attribute-based credential (ABC) system, users obtain a digital certificate on their personal attributes, and can later prove possession of such a certificate in an unlinkable way, thereby selectively disclosing chosen attributes to the service provider. Recently, the concept of encrypted ABCs (EABCs) was introduced by Krenn et al. at CANS 2017, where virtually all computation is outsourced to a semi-trusted cloud-provider called wallet, thereby overcoming existing efficiency limitations on the user’s side, and for the first time enabling “privacy-preserving identity management as a service”. While their approach is highly relevant for bringing ABCs into the real world, we present a simple attack allowing the wallet to learn a user\u27s attributes when colluding with another user -- a scenario which is not covered by their modeling but which needs to be considered in practice. We then revise the model and construction of Krenn et al. in various ways, such that the above attack is no longer possible. Furthermore, we also remove existing non-collusion assumptions between wallet and service provider or issuer from their construction. Our protocols are still highly efficient in the sense that the computational effort on the end user side consists of a single exponentiation only, and otherwise efficiency is comparable to the original work of Krenn et al

{SoK}: {An} Analysis of Protocol Design: Avoiding Traps for Implementation and Deployment

Today's Internet utilizes a multitude of different protocols. While some of these protocols were first implemented and used and later documented, other were first specified and then implemented. Regardless of how protocols came to be, their definitions can contain traps that lead to insecure implementations or deployments. A classical example is insufficiently strict authentication requirements in a protocol specification. The resulting Misconfigurations, i.e., not enabling strong authentication, are common root causes for Internet security incidents. Indeed, Internet protocols have been commonly designed without security in mind which leads to a multitude of misconfiguration traps. While this is slowly changing, to strict security considerations can have a similarly bad effect. Due to complex implementations and insufficient documentation, security features may remain unused, leaving deployments vulnerable. In this paper we provide a systematization of the security traps found in common Internet protocols. By separating protocols in four classes we identify major factors that lead to common security traps. These insights together with observations about end-user centric usability and security by default are then used to derive recommendations for improving existing and designing new protocols---without such security sensitive traps for operators, implementors and users

{SoK}: {An} Analysis of Protocol Design: Avoiding Traps for Implementation and Deployment

Today's Internet utilizes a multitude of different protocols. While some of these protocols were first implemented and used and later documented, other were first specified and then implemented. Regardless of how protocols came to be, their definitions can contain traps that lead to insecure implementations or deployments. A classical example is insufficiently strict authentication requirements in a protocol specification. The resulting Misconfigurations, i.e., not enabling strong authentication, are common root causes for Internet security incidents. Indeed, Internet protocols have been commonly designed without security in mind which leads to a multitude of misconfiguration traps. While this is slowly changing, to strict security considerations can have a similarly bad effect. Due to complex implementations and insufficient documentation, security features may remain unused, leaving deployments vulnerable. In this paper we provide a systematization of the security traps found in common Internet protocols. By separating protocols in four classes we identify major factors that lead to common security traps. These insights together with observations about end-user centric usability and security by default are then used to derive recommendations for improving existing and designing new protocols---without such security sensitive traps for operators, implementors and users

Federated identity architecture of the european eID system

Federated identity management is a method that facilitates management of identity processes and policies among the collaborating entities without a centralized control. Nowadays, there are many federated identity solutions, however, most of them covers different aspects of the identification problem, solving in some cases specific problems. Thus, none of these initiatives has consolidated as a unique solution and surely it will remain like that in a near future. To assist users choosing a possible solution, we analyze different federated identify approaches, showing main features, and making a comparative study among them. The former problem is even worst when multiple organizations or countries already have legacy eID systems, as it is the case of Europe. In this paper, we also present the European eID solution, a purely federated identity system that aims to serve almost 500 million people and that could be extended in midterm also to eID companies. The system is now being deployed at the EU level and we present the basic architecture and evaluate its performance and scalability, showing that the solution is feasible from the point of view of performance while keeping security constrains in mind. The results show a good performance of the solution in local, organizational, and remote environments

Token Based Authentication and Authorization with Zero-Knowledge Proofs for Enhancing Web API Security and Privacy

This design science study showcases an innovative artifact that utilizes Zero-Knowledge Proofs for API Authentication and Authorization. A comprehensive examination of existing literature and technology is conducted to evaluate the effectiveness of this alternative approach. The study reveals that existing APIs are using slower techniques that don’t scale, can’t take advantage of newer hardware, and have been unable to adequately address current security issues. In contrast, the novel technique presented in this study performs better, is more resilient in privacy sensitive and security settings, and is easy to implement and deploy. Additionally, this study identifies potential avenues for further research that could help advance the field of Web API development in terms of security, privacy, and simplicity

Security and Privacy for IoT Ecosystems

Smart devices have become an integral part of our everyday life. In contrast to smartphones and laptops, Internet of Things (IoT) devices are typically managed by the vendor. They allow little or no user-driven customization. Users need to use and trust IoT devices as they are, including the ecosystems involved in the processing and sharing of personal data. Ensuring that an IoT device does not leak private data is imperative. This thesis analyzes security practices in popular IoT ecosystems across several price segments. Our results show a gap between real-world implementations and state-of-the-art security measures. The process of responsible disclosure with the vendors revealed further practical challenges. Do they want to support backward compatibility with the same app and infrastructure over multiple IoT device generations? To which extent can they trust their supply chains in rolling out keys? Mature vendors have a budget for security and are aware of its demands. Despite this goodwill, developers sometimes fail at securing the concrete implementations in those complex ecosystems. Our analysis of real-world products reveals the actual efforts made by vendors to secure their products. Our responsible disclosure processes and publications of design recommendations not only increase security in existing products but also help connected ecosystem manufacturers to develop secure products. Moreover, we enable users to take control of their connected devices with firmware binary patching. If a vendor decides to no longer offer cloud services, bootstrapping a vendor-independent ecosystem is the only way to revive bricked devices. Binary patching is not only useful in the IoT context but also opens up these devices as research platforms. We are the first to publish tools for Bluetooth firmware and lower-layer analysis and uncover a security issue in Broadcom chips affecting hundreds of millions of devices manufactured by Apple, Samsung, Google, and more. Although we informed Broadcom and customers of their technologies of the weaknesses identified, some of these devices no longer receive official updates. For these, our binary patching framework is capable of building vendor-independent patches and retrofit security. Connected device vendors depend on standards; they rarely implement lower-layer communication schemes from scratch. Standards enable communication between devices of different vendors, which is crucial in many IoT setups. Secure standards help making products secure by design and, thus, need to be analyzed as early as possible. One possibility to integrate security into a lower-layer standard is Physical-Layer Security (PLS). PLS establishes security on the Physical Layer (PHY) of wireless transmissions. With new wireless technologies emerging, physical properties change. We analyze how suitable PLS techniques are in the domain of mmWave and Visible Light Communication (VLC). Despite VLC being commonly believed to be very secure due to its limited range, we show that using VLC instead for PLS is less secure than using it with Radio Frequency (RF) communication. The work in this thesis is applied to mature products as well as upcoming standards. We consider security for the whole product life cycle to make connected devices and IoT ecosystems more secure in the long term

Spartan Daily, February 7, 2006

Volume 126, Issue 7https://scholarworks.sjsu.edu/spartandaily/10207/thumbnail.jp

Spartan Daily, February 7, 2006

Volume 126, Issue 7https://scholarworks.sjsu.edu/spartandaily/10207/thumbnail.jp