IMDfence: Architecting a Secure Protocol for Implantable Medical Devices

Over the past decade, focus on the security and privacy aspects of implantable medical devices (IMDs) has intensified, driven by the multitude of cybersecurity vulnerabilities found in various existing devices. However, due to their strict computational, energy and physical constraints, conventional security protocols are not directly applicable to IMDs. Custom-tailored schemes have been proposed instead which, however, fail to cover the full spectrum of security features that modern IMDs and their ecosystems so critically require. In this paper we propose IMDfence, a security protocol for IMD ecosystems that provides a comprehensive yet practical security portfolio, which includes availability, non-repudiation, access control, entity authentication, remote monitoring and system scalability. The protocol also allows emergency access that results in the graceful degradation of offered services without compromising security and patient safety. The performance of the security protocol as well as its feasibility and impact on modern IMDs are extensively analyzed and evaluated. We find that IMDfence achieves the above security requirements at a mere less than 7% increase in total IMD energy consumption, and less than 14 ms and 9 kB increase in system delay and memory footprint, respectively

Mobile Identity, Credential, and Access Management Framework

Organizations today gather unprecedented quantities of data from their operations. This data is coming from transactions made by a person or from a connected system/application. From personal devices to industry including government, the internet has become the primary means of modern communication, further increasing the need for a method to track and secure these devices. Protecting the integrity of connected devices collecting data is critical to ensure the trustworthiness of the system. An organization must not only know the identity of the users on their networks and have the capability of tracing the actions performed by a user but they must trust the system providing them with this knowledge. This increase in the pace of usage of personal devices along with a lack of trust in the internet has driven demand for trusted digital identities. As the world becomes increasingly mobile with the number of smart phone users growing annually and the mobile web flourishing, it is critical to implement strong security on mobile devices. To manage the vast number of devices and feel confident that a machine’s identity is verifiable, companies need to deploy digital credentialing systems with a strong root of trust. As passwords are not a secure method of authentication, mobile devices and other forms of IoT require a means of two-factor authentication that meets NIST standards. Traditionally, this has been done with Public Key Infrastructure (PKI) through the use of a smart card. Blockchain technologies combined with PKI can be utilized in such a way as to provide an identity and access management solution for the internet of things (IoT). Improvements to the security of Radio Frequency Identification (RFID) technology and various implementations of blockchain make viable options for managing the identity and access of IoT devices. When PKI first began over two decades ago, it required the use of a smart card with a set of credentials known as the personal identity verification (PIV) card. The PIV card (something you have) along with a personal identification number (PIN) (something you know) were used to implement two-factor authentication. Over time the use of the PIV cards has proven challenging as mobile devices lack the integrated smart card readers found in laptop and desktop computers. Near Field Communication (NFC) capability in most smart phones and mobile devices provides a mechanism to allow a PIV card to be read by a mobile device. In addition, the existing PKI system must be updated to meet the demands of a mobile focused internet. Blockchain technology is the key to modernizing PKI. Together, blockchain-based PKI and NFC will provide an IoT solution that will allow industry, government, and individuals a foundation of trust in the world wide web that is lacking today

A Mobile Secure Bluetooth-Enabled Cryptographic Provider

The use of digital X509v3 public key certificates, together with different standards for secure digital signatures are commonly adopted to establish authentication proofs between principals, applications and services. One of the robustness characteristics commonly associated with such mechanisms is the need of hardware-sealed cryptographic devices, such as Hardware-Security Modules (or HSMs), smart cards or hardware-enabled tokens or dongles. These devices support internal functions for management and storage of cryptographic keys, allowing the isolated execution of cryptographic operations, with the keys or related sensitive parameters never exposed. The portable devices most widely used are USB-tokens (or security dongles) and internal ships of smart cards (as it is also the case of citizen cards, banking cards or ticketing cards). More recently, a new generation of Bluetooth-enabled smart USB dongles appeared, also suitable to protect cryptographic operations and digital signatures for secure identity and payment applications. The common characteristic of such devices is to offer the required support to be used as secure cryptographic providers. Among the advantages of those portable cryptographic devices is also their portability and ubiquitous use, but, in consequence, they are also frequently forgotten or even lost. USB-enabled devices imply the need of readers, not always and not commonly available for generic smartphones or users working with computing devices. Also, wireless-devices can be specialized or require a development effort to be used as standard cryptographic providers. An alternative to mitigate such problems is the possible adoption of conventional Bluetooth-enabled smartphones, as ubiquitous cryptographic providers to be used, remotely, by client-side applications running in users’ devices, such as desktop or laptop computers. However, the use of smartphones for safe storage and management of private keys and sensitive parameters requires a careful analysis on the adversary model assumptions. The design options to implement a practical and secure smartphone-enabled cryptographic solution as a product, also requires the approach and the better use of the more interesting facilities provided by frameworks, programming environments and mobile operating systems services. In this dissertation we addressed the design, development and experimental evaluation of a secure mobile cryptographic provider, designed as a mobile service provided in a smartphone. The proposed solution is designed for Android-Based smartphones and supports on-demand Bluetooth-enabled cryptographic operations, including standard digital signatures. The addressed mobile cryptographic provider can be used by applications running on Windows-enabled computing devices, requesting digital signatures. The solution relies on the secure storage of private keys related to X509v3 public certificates and Android-based secure elements (SEs). With the materialized solution, an application running in a Windows computing device can request standard digital signatures of documents, transparently executed remotely by the smartphone regarded as a standard cryptographic provider

Offloading cryptographic services to the SIM card in smartphones

Smartphones have achieved ubiquitous presence in people’s everyday life as communication, entertainment and work tools. Touch screens and a variety of sensors offer a rich experience and make applications increasingly diverse, complex and resource demanding. Despite their continuous evolution and enhancements, mobile devices are still limited in terms of battery life, processing power, storage capacity and network bandwidth. Computation offloading stands out among the efforts to extend device capabilities and face the growing gap between demand and availability of resources. As most popular technologies, mobile devices are attractive targets for malicious at- tackers. They usually store sensitive private data of their owners and are increasingly used for security sensitive activities such as online banking or mobile payments. While computation offloading introduces new challenges to the protection of those assets, it is very uncommon to take security and privacy into account as the main optimization objectives of this technique. Mobile OS security relies heavily on cryptography. Available hardware and software cryptographic providers are usually designed to resist software attacks. This kind of protection is not enough when physical control over the device is lost. Secure elements, on the other hand, include a set of protections that make them physically tamper-resistant devices. This work proposes a computation offloading technique that prioritizes enhancing security capabilities in mobile phones by offloading cryptographic operations to the SIM card, the only universally present secure element in those devices. Our contributions include an architecture for this technique, a proof-of-concept prototype developed under Android OS and the results of a performance evaluation that was conducted to study its execution times and battery consumption. Despite some limitations, our approach proves to be a valid alternative to enhance security on any smartphone.Los smartphones están omnipresentes en la vida cotidiana de las personas como herramientas de comunicación, entretenimiento y trabajo. Las pantallas táctiles y una variedad de sensores ofrecen una experiencia superior y hacen que las aplicaciones sean cada vez más diversas, complejas y demanden más recursos. A pesar de su continua evolución y mejoras, los dispositivos móviles aún están limitados en duración de batería, poder de procesamiento, capacidad de almacenamiento y ancho de banda de red. Computation offloading se destaca entre los esfuerzos para ampliar las capacidades del dispositivo y combatir la creciente brecha entre demanda y disponibilidad de recursos. Como toda tecnología popular, los smartphones son blancos atractivos para atacantes maliciosos. Generalmente almacenan datos privados y se utilizan cada vez más para actividades sensibles como banca en línea o pagos móviles. Si bien computation offloading presenta nuevos desafíos al proteger esos activos, es muy poco común tomar seguridad y privacidad como los principales objetivos de optimización de dicha técnica. La seguridad del SO móvil depende fuertemente de la criptografía. Los servicios criptográficos por hardware y software disponibles suelen estar diseñados para resistir ataques de software, protección insuficiente cuando se pierde el control físico sobre el dispositivo. Los elementos seguros, en cambio, incluyen un conjunto de protecciones que los hacen físicamente resistentes a la manipulación. Este trabajo propone una técnica de computation offloading que prioriza mejorar las capacidades de seguridad de los teléfonos móviles descargando operaciones criptográficas a la SIM, único elemento seguro universalmente presente en los mismos. Nuestras contribuciones incluyen una arquitectura para esta técnica, un prototipo de prueba de concepto desarrollado bajo Android y los resultados de una evaluación de desempeño que estudia tiempos de ejecución y consumo de batería. A pesar de algunas limitaciones, nuestro enfoque demuestra ser una alternativa válida para mejorar la seguridad en cualquier smartphone

ARPA Whitepaper

We propose a secure computation solution for blockchain networks. The correctness of computation is verifiable even under malicious majority condition using information-theoretic Message Authentication Code (MAC), and the privacy is preserved using Secret-Sharing. With state-of-the-art multiparty computation protocol and a layer2 solution, our privacy-preserving computation guarantees data security on blockchain, cryptographically, while reducing the heavy-lifting computation job to a few nodes. This breakthrough has several implications on the future of decentralized networks. First, secure computation can be used to support Private Smart Contracts, where consensus is reached without exposing the information in the public contract. Second, it enables data to be shared and used in trustless network, without disclosing the raw data during data-at-use, where data ownership and data usage is safely separated. Last but not least, computation and verification processes are separated, which can be perceived as computational sharding, this effectively makes the transaction processing speed linear to the number of participating nodes. Our objective is to deploy our secure computation network as an layer2 solution to any blockchain system. Smart Contracts\cite{smartcontract} will be used as bridge to link the blockchain and computation networks. Additionally, they will be used as verifier to ensure that outsourced computation is completed correctly. In order to achieve this, we first develop a general MPC network with advanced features, such as: 1) Secure Computation, 2) Off-chain Computation, 3) Verifiable Computation, and 4)Support dApps' needs like privacy-preserving data exchange

A Survey on Smart Home Authentication: Toward Secure, Multi-Level and Interaction-based Identification

With the increased number and reduced cost of smart devices, Internet of Things (IoT) applications such as smart home (SHome) are increasingly popular. Owing to the characteristics of IoT environments such as resource constrained devices, existing authentication solutions may not be suitable to secure these environments. As a result, a number of authentication solutions specifically designed for IoT environments have been proposed. This paper provides a critical analysis of existing authentication solutions. The major contributions of the paper are as follows. First, it presents a generic model derived from an SHome use-case scenario. Secondly, based on the model, it performs a threat analysis to identify possible means of attacks. The analysis leads to the specification of a set of desirable security requirements for the design of authentication solutions for SHome. Thirdly, based on the requirements, existing authentication solutions are analysed and some ideas for achieving effective and efficient authentication in IoT environments are proposed

Authentication Protocols and Privacy Protection

Tato dizertační práce se zabývá kryptografickými prostředky pro autentizaci. Hlavním tématem však nejsou klasické autentizační protokoly, které nabízejí pouze ověření identity, ale tzv. atributové autentizační systémy, pomocí kterých mohou uživatelé prokazovat svoje osobní atributy. Tyto atributy pak mohou představovat jakékoliv osobní informace, např. věk, národnost či místo narození. Atributy mohou být prokazovány anonymně a s podporou mnoha funkcí na ochranu digitální identity. Mezi takové funkce patří např. nespojitelnost autentizačních relací, nesledovatelnost, možnost výběru prokazovaných atributů či efektivní revokace. Atributové autentizační systémy jsou již nyní považovány za nástupce současných systémů v oficiálních strategických plánech USA (NSTIC) či EU (ENISA). Část požadovaných funkcí je již podporována existujícími kryptografickými koncepty jako jsou U-Prove či idemix. V současné době však není známý systém, který by poskytoval všechny potřebné funkce na ochranu digitální identity a zároveň byl prakticky implementovatelný na zařízeních, jako jsou čipové karty. Mezi klíčové slabiny současných systémů patří především chybějící nespojitelnost relací a absence revokace. Není tak možné efektivně zneplatnit zaniklé uživatele, ztracené či ukradené autentizační karty či karty škodlivých uživatelů. Z těchto důvodů je v této práci navrženo kryptografické schéma, které řeší slabiny nalezené při analýze existujících řešení. Výsledné schéma, jehož návrh je založen na ověřených primitivech, jako jsou $\Sigma$-protokoly pro důkazy znalostí, kryptografické závazky či ověřitelné šifrování, pak podporuje všechny požadované vlastnosti pro ochranu soukromí a digitální identity. Zároveň je však návrh snadno implementovatelný v prostředí smart-karet. Tato práce obsahuje plný kryptografický návrh systému, formální ověření klíčových vlastností, matematický model schématu v programu Mathematica pro ověření funkčnosti a výsledky experimentální implementace v prostředí .NET smart-karet. I přesto, že navrhovaný systém obsahuje podporu všech funkcí na ochranu soukromí, včetně těch, které chybí u existujících systémů, jeho výpočetní složitost zůstává stejná či nižší, doba ověření uživatele je tedy kratší než u existujících systémů. Výsledkem je schéma, které může velmi znatelně zvýšit ochranu soukromí uživatelů při jejich ověřování, především při využití v elektronických dokladech, přístupových systémech či Internetových službách.This dissertation thesis deals with the cryptographic constructions for user authentication. Rather than classical authentication protocols which allow only the identity verification, the attribute authentication systems are the main topic of this thesis. The attribute authentication systems allow users to give proofs about the possession of personal attributes. These attributes can represent any personal information, for example age, nationality or birthplace. The attribute ownership can be proven anonymously and with the support of many features for digital identity protection. These features include, e.g., the unlinkability of verification sessions, untraceability, selective disclosure of attributes or efficient revocation. Currently, the attribute authentication systems are considered to be the successors of existing authentication systems by the official strategies of USA (NSTIC) and EU (ENISA). The necessary features are partially provided by existing cryptographic concepts like U-Prove and idemix. But at this moment, there is no system providing all privacy-enhancing features which is implementable on computationally restricted devices like smart-cards. Among all weaknesses of existing systems, the missing unlinkability of verification sessions and the absence of practical revocation are the most critical ones. Without these features, it is currently impossible to invalidate expired users, lost or stolen authentication cards and cards of malicious users. Therefore, a new cryptographic scheme is proposed in this thesis to fix the weaknesses of existing schemes. The resulting scheme, which is based on established primitives like $\Sigma$-protocols for proofs of knowledge, cryptographic commitments and verifiable encryption, supports all privacy-enhancing features. At the same time, the scheme is easily implementable on smart-cards. This thesis includes the full cryptographic specification, the formal verification of key properties, the mathematical model for functional verification in Mathematica software and the experimental implementation on .NET smart-cards. Although the scheme supports all privacy-enhancing features which are missing in related work, the computational complexity is the same or lower, thus the time of verification is shorter than in existing systems. With all these features and properties, the resulting scheme can significantly improve the privacy of users during their verification, especially when used in electronic ID systems, access systems or Internet services.