Privacy preserving protocols for smart meters and electric vehicles

Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2015Actualmente existe a tendência para se adicionar mais inteligência em vários pontos da rede elétrica, permitindo uma comunicação bidireccional entre a empresa fornecedora de energia eléctrica e as nossas casas. Ao longo dos próximos anos, os contadores de energia nas nossas casas serão gradualmente substituídos por um equipamento com mais capacidades, denominado medidor inteligente. Os medidores inteligentes podem colher informações sobre os gastos de energia em tempo real, e encaminhar os dados para o fornecedor. Além disso, podem receber comandos do fornecedor (ou outros intervenientes) e agir em conformidade, nomeadamente através da interacção com equipamentos locais (por exemplo, ar condicionado ou congelador) para ajustar o seu modo de operação, diminuindo temporariamente o consumo de energia. Os medidores inteligentes podem ainda apoiar a produção local de energia (com painéis solares ou geradores eólicos) e o seu armazenamento (através de um banco de baterias ou veículo eléctrico), sendo necessário haver coordenação entre a sua operação e as empresas fornecedoras de energia eléctrica. Estes medidores, quando coordenados de uma forma apropriada, podem permitir uma redução dos picos globais de consumo. Deste modo evitam investimentos na rede energética direccionados para lidar com estas condições extremas, que tendem a ocorrer durante o horário laboral. A evolução no uso de veículos eléctricos irá gerar também um grande consumo de energia. Caso todos os veículos se tornem eléctricos, a rede actual não tem capacidade para lidar com o enorme pico gerado. No entanto, estes veículos poderão também ter a capacidade de transferir para a rede parte da sua energia, o que significa que, poderão ser usados em caso de necessidade para colmatar flutuações no consumo de energia (juntamente com outras fontes alternativas de geração). Esta coordenação, quando eficiente, pode permitir grandes vantagens em situações limite, como por exemplo quando há um fornecimento reduzido de energia, em que os medidores podem desactivar total ou parcialmente os aparelhos domésticos, permitindo uma melhor distribuição de energia por todos, priorizando, se necessário, certos locais como por exemplo hospitais. Como esperado, este tipo de configuração é propenso a muitas formas de ataque, desde a espionagem de comunicações até à manipulação física dos medidores inteligentes. Por isso, é necessário desenvolver protocolos seguros que possam ser usados para proteger os dispositivos e aplicações que irão operar na rede eléctrica futura. Este projecto em particular, desenvolve uma solução que protege as comunicações entre o medidor inteligente e a empresa distribuidora de energia no que diz respeito aos ataques à privacidade. Nestes ataques, o adversário obtém informação sobre o que o utilizador está a fazer em sua casa, monitorizando em tempo real a informação que é transmitida pelo medidor inteligente. Nos últimos anos tem-se assistido igualmente a uma evolução rápida nas tecnologias de transferência de energia sem fios, existindo actualmente alguns protótipos em funcionamento, como o carregamento de baterias em autocarros eléctricos numa universidade da Coreia do Sul. Uma eventual utilização generalizada desta tecnologia obriga à definição de novas formas de pagamento, possibilitando que os veículos eléctricos se possam abastecer em movimento. Se existir um protocolo demasiado simples que faça esta tarefa, pode levar a que o condutor seja identificado quando e onde carregar as baterias do seu veículo, algo que não acontece com um tradicional abastecimento de combustível pago com notas ou moedas. Este projecto lida com duas vertentes relacionadas que tratam da aferição do consumo de energia. Uma é baseada nos contadores inteligentes das casas, e outra nos “contadores” em veículos (mais concretamente, a forma de pagamento da energia transferida sem fios para um veículo em movimento). Apresentam-se diferentes técnicas/algoritmos já propostos que podem contribuir para uma solução, mas que apesar disso não conseguem atingir todos os requisitos e funcionalidades pretendidas de forma isolada. Estabelece-se também uma relação com o trabalho já realizado que utiliza tais técnicas. É estudado um protocolo especifico, o Low Overhead PrivAcy (LOPA), que organiza vários medidores num grupo. Em cada grupo é gerada secretamente uma chave entre cada medidor do grupo, depois é criada a partir dessa chave uma outra chave, que é somada a cada medição que cada medidor envia para um agregador, sem que ninguém consiga ver o valor da medição individual (devido à chave). O agregador, ao somar todas as medições de todos os medidores de um grupo, obtém o valor total de consumo de todos os medidores. O agregador, no entanto, não consegue saber cada medição individual, devido ao modo como a chave é gerada, garantindo a privacidade de cada casa. Este protocolo é explicado em detalhe, implementado e avaliado. São propostos também três protocolos para o pagamento da transferência de energia, que permitem manter o anonimato de um veículo, evitando que se saiba quando ou onde este circula. Os protocolos também lidam com ineficiências de transmissão, assegurando uma rapidez, simplicidade e segurança adequadas para serem aplicados em carros em movimento a velocidades habituais de circulação. Um dos protocolos permite uma transferência de energia pós-paga, e os outros dois usam uma modalidade de pré-pagamento, um com contas temporárias e o outro com dinheiro digital. Estes protocolos baseiam-se num conjunto de mensagens que empregam técnicas como assinaturas digitais (para garantir a integridade e autenticação das comunicações), técnicas de cifra, dinheiro digital, ou entidades terceiras confiáveis para permitir a confidencialidade. Pretende-se que seja assegurada a segurança do pagamento, ao mesmo tempo que é permitido ao ponto de carregamento identificar o responsável pelo veículo, em caso de incumprimento. O dinheiro digital e o protocolo de perfis pseudo-anónimos foram implementados e avaliados em duas plataformas diferentes. Os resultados experimentais foram muito satisfatórios, dando indicações de que estes protocolos poderiam ser utilizados na prática.There is currently a trend to add more intelligence to various points of the electric grid, thus enabling a bidirectional communication path between the electrical utility company and our homes, by upgrading the existing components along the way. For example, the metering devices in our homes will be gradually replaced with a more capable equipment, called smart meter. Smart meters can collect information about energy spending in real-time, and forward this data to the utility. Moreover, they can receive information from the utility (or other operators) and act on it, for instance, by interacting with local equipments (e.g., air conditioner or refrigerator) to adjust their operation mode (e.g., make them decrease the energy use). Smart meters can also support local energy production (e.g., solar panels or windmills) and storage (e.g., batteries), by coordinating its operation with the utility companies. As expected, this sort of setting is prone to many forms of attack, ranging from eavesdropping on the communications to the physical tampering of the smart meters. Therefore, it is necessary to develop secure protocols that can be used to protect the devices and applications that will be operating in this future smart grid. In particular, in this project we study and evaluate a solution that protects the communications between the smart meter and the electrical company with respect to attacks on privacy. For instance, it addresses a form of attack where the adversary learns information about what a person is doing at home by monitoring the messages transmitted by the smart meter in real-time. In recent years there have been rapid developments in Wireless Power Transfer technology (WPT). There are currently some prototypes in operation, such as charging batteries in electric buses at a university in South Korea. In the event of a widespread use of this technology, it is required that new forms of accounting and payment of energy are established. This project proposes a protocol for the payment of energy transfer that ensures the anonymity of the vehicle, precluding attacks that attempt to determine where it circulates. The protocol also handles transmission inefficiencies, ensuring a fast, simple and adequate application in cars moving at normal speeds of movement

Seamless key agreement framework for mobile-sink in IoT based cloud-centric secured public safety sensor networks

Recently, the Internet of Things (IoT) has emerged as a significant advancement for Internet and mobile networks with various public safety network applications. An important use of IoT-based solutions is its application in post-disaster management, where the traditional telecommunication systems may be either completely or partially damaged. Since enabling technologies have restricted authentication privileges for mobile users, in this paper, a strategy of mobile-sink is introduced for the extension of user authentication over cloud-based environments. A seamless secure authentication and key agreement (S-SAKA) approach using bilinear pairing and elliptic-curve cryptosystems is presented. It is shown that the proposed S-SAKA approach satisfies the security properties, and as well as being resilient to nodecapture attacks, it also resists significant numbers of other well-known potential attacks related with data confidentiality, mutual authentication, session-key agreement, user anonymity, password guessing, and key impersonation. Moreover, the proposed approach can provide a seamless connectivity through authentication over wireless sensor networks to alleviate the computation and communication cost constraints in the system. In addition, using Burrows–Abadi–Needham logic, it is demonstrated that the proposed S-SAKA framework offers proper mutual authentication and session key agreement between the mobile-sink and the base statio

Seamless key agreement framework for mobile-sink in IoT based cloud-centric secured public safety sensor networks

Recently, the Internet of Things (IoT) has emerged as a significant advancement for Internet and mobile networks with various public safety network applications. An important use of IoT-based solutions is its application in post-disaster management, where the traditional telecommunication systems may be either completely or partially damaged. Since enabling technologies have restricted authentication privileges for mobile users, in this paper, a strategy of mobile-sink is introduced for the extension of user authentication over cloud-based environments. A seamless secure authentication and key agreement (S-SAKA) approach using bilinear pairing and elliptic-curve cryptosystems is presented. It is shown that the proposed S-SAKA approach satisfies the security properties, and as well as being resilient to nodecapture attacks, it also resists significant numbers of other well-known potential attacks related with data confidentiality, mutual authentication, session-key agreement, user anonymity, password guessing, and key impersonation. Moreover, the proposed approach can provide a seamless connectivity through authentication over wireless sensor networks to alleviate the computation and communication cost constraints in the system. In addition, using Burrows–Abadi–Needham logic, it is demonstrated that the proposed S-SAKA framework offers proper mutual authentication and session key agreement between the mobile-sink and the base statio

TD2SecIoT: Temporal, Data-Driven and Dynamic Network Layer Based Security Architecture for Industrial IoT

The Internet of Things (IoT) is an emerging technology, which comprises wireless smart sensors and actuators. Nowadays, IoT is implemented in different areas such as Smart Homes, Smart Cities, Smart Industries, Military, eHealth, and several real-world applications by connecting domain-specific sensors. Designing a security model for these applications is challenging for researchers since attacks (for example, zero-day) are increasing tremendously. Several security methods have been developed to ensure the CIA (Confidentiality, Integrity, and Availability) for Industrial IoT (IIoT). Though these methods have shown promising results, there are still some security issues that are open. Thus, the security and authentication of IoT based applications become quite significant. In this paper, we propose TD2SecIoT (Temporal, Data-Driven and Dynamic Network Layer Based Security Architecture for Industrial IoT), which incorporates Elliptic Curve Cryptography (ECC) and Nth-degree Truncated Polynomial Ring Units (NTRU) methods to ensure confidentiality and integrity. The proposed method has been evaluated against different attacks and performance measures (quantitative and qualitative) using the Cooja network simulator with Contiki-OS. The TD2SecIoT has shown a higher security level with reduced computational cost and time

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

SECURE BOOTSTRAPPING AND ACCESS CONTROL IN NDN-BASED SMART HOME SYSTEMS

Smart home systems utilize network-enabled sensors to collect environmental data and provide various services to home residents. Such a system must be designed with security mechanisms to protect the safety and privacy of the residents. More specifically, we need to secure the production, dissemination, and consumption of smart home data, as well as prevent any unauthorized access to the services provided by the system. In this work, we study how to build a secure smart home system in the context of Named Data Networking, a future Internet architecture that has unique advantages in securing Internet of Things. We focus on solving two security problems: (a) mutual authentication between a new device and an existing smart home system to bootstrap the device, and (b) controlling access to smart home data. We designed a naming hierarchy for a smart home system and the corresponding trust model. Based on the naming and trust model, we designed bootstrapping protocols which enforce mutual cryptographic challenges, and a programming template which facilitates Name-based Access Control. We have designed and implemented an application that incorporates these solutions. Evaluation result shows: (a) the bootstrapping protocols can defend against replay attacks with a small computation overhead, and (b) Name-Based Access Control can provide accurate time schedules to restrict access to fine-grained data types with a small computation overhead

A survey of secure middleware for the Internet of Things

The rapid growth of small Internet connected devices, known as the Internet of Things (IoT), is creating a new set of challenges to create secure, private infrastructures. This paper reviews the current literature on the challenges and approaches to security and privacy in the Internet of Things, with a strong focus on how these aspects are handled in IoT middleware. We focus on IoT middleware because many systems are built from existing middleware and these inherit the underlying security properties of the middleware framework. The paper is composed of three main sections. Firstly, we propose a matrix of security and privacy threats for IoT. This matrix is used as the basis of a widespread literature review aimed at identifying requirements on IoT platforms and middleware. Secondly, we present a structured literature review of the available middleware and how security is handled in these middleware approaches. We utilise the requirements from the first phase to evaluate. Finally, we draw a set of conclusions and identify further work in this area

Algebraic Curves and Cryptographic Protocols for the e-society

Amb l'augment permanent de l'adopció de sistemes intel·ligents de tot tipus en la societat actual apareixen nous reptes. Avui en dia quasi tothom en la societat moderna porta a sobre almenys un telèfon intel·ligent, si no és que porta encara més dispositius capaços d'obtenir dades personals, com podria ser un smartwatch per exemple. De manera similar, pràcticament totes les cases tindran un comptador intel·ligent en el futur pròxim per a fer un seguiment del consum d'energia. També s'espera que molts més dispositius del Internet de les Coses siguin instal·lats de manera ubiqua, recol·lectant informació dels seus voltants i/o realitzant accions, com per exemple en sistemes d'automatització de la llar, estacions meteorològiques o dispositius per la ciutat intel·ligent en general. Tots aquests dispositius i sistemes necessiten enviar dades de manera segura i confidencial, les quals poden contindre informació sensible o de caire privat. A més a més, donat el seu ràpid creixement, amb més de nou mil milions de dispositius en tot el món actualment, s'ha de tenir en compte la quantitat de dades que cal transmetre. En aquesta tesi mostrem la utilitat de les corbes algebraiques sobre cossos finits en criptosistemes de clau pública, en particular la de les corbes de gènere 2, ja que ofereixen la mida de clau més petita per a un nivell de seguretat donat i això redueix de manera significativa el cost total de comunicacions d'un sistema, a la vegada que manté un rendiment raonable. Analitzem com la valoració 2-àdica del cardinal de la Jacobiana augmenta en successives extensions quadràtiques, considerant corbes de gènere 2 en cossos de característica senar, incloent les supersingulars. A més, millorem els algoritmes actuals per a computar la meitat d'un divisor d'una corba de gènere 2 sobre un cos binari, cosa que pot ser útil en la multiplicació escalar, que és l'operació principal en criptografia de clau pública amb corbes. Pel que fa a la privacitat, presentem un sistema de pagament d'aparcament per mòbil que permet als conductors pagar per aparcar mantenint la seva privacitat, i per tant impedint que el proveïdor del servei o un atacant obtinguin un perfil de conducta d'aparcament. Finalment, oferim protocols de smart metering millorats, especialment pel que fa a la privacitat i evitant l'ús de terceres parts de confiança.Con el aumento permanente de la adopción de sistemas inteligentes de todo tipo en la sociedad actual aparecen nuevos retos. Hoy en día prácticamente todos en la sociedad moderna llevamos encima al menos un teléfono inteligente, si no es que llevamos más dispositivos capaces de obtener datos personales, como podría ser un smartwatch por ejemplo. De manera similar, en el futuro cercano la mayoría de las casas tendrán un contador inteligente para hacer un seguimiento del consumo de energía. También se espera que muchos más dispositivos del Internet de las Cosas sean instalados de manera ubicua, recolectando información de sus alrededores y/o realizando acciones, como por ejemplo en sistemas de automatización del hogar, estaciones meteorológicas o dispositivos para la ciudad inteligente en general. Todos estos dispositivos y sistemas necesitan enviar datos de manera segura y confidencial, los cuales pueden contener información sensible o de ámbito personal. Además, dado su rápido crecimiento, con más de nueve mil millones de dispositivos en todo el mundo actualmente, hay que tener en cuenta la cantidad de datos a transmitir. En esta tesis mostreamos la utilidad de las curvas algebraicas sobre cuerpos finitos en criptosistemas de clave pública, en particular la de las curvas de género 2, ya que ofrecen el tamaño de clave más pequeño para un nivel de seguridad dado y esto disminuye de manera significativa el coste total de comunicaciones del sistema, a la vez que mantiene un rendimiento razonable. Analizamos como la valoración 2-ádica del cardinal de la Jacobiana aumenta en sucesivas extensiones cuadráticas, considerando curvas de género 2 en cuerpos de característica importa, incluyendo las supersingulares. Además, mejoramos los algoritmos actuales para computar la mitad de un divisor de una curva de género 2 sobre un cuerpo binario, lo cual puede ser útil en la multiplicación escalar, que es la operación principal en criptografía de clave pública con curvas. Respecto a la privacidad, presentamos un sistema de pago de aparcamiento por móvil que permite a los conductores pagar para aparcar manteniendo su privacidad, y por lo tanto impidiendo que el proveedor del servicio o un atacante obtengan un perfil de conducta de aparcamiento. Finalmente, ofrecemos protocolos de smart metering mejorados, especialmente en lo relativo a la privacidad y evitando el uso de terceras partes de confianza.With the ever increasing adoption of smart systems of every kind throughout society, new challenges arise. Nowadays, almost everyone in modern societies carries a smartphone at least, if not even more devices than can also gather personal data, like a smartwatch or a fitness wristband for example. Similarly, practically all homes will have a smart meter in the near future for billing and energy consumption monitoring, and many other Internet of Things devices are expected to be installed ubiquitously, obtaining information of their surroundings and/or performing some action, like for example, home automation systems, weather detection stations or devices for the smart city in general. All these devices and systems need to securely and privately transmit some data, which can be sensitive and personal information. Moreover, with a rapid increase of their number, with already more than nine billion devices worldwide, the amount of data to be transmitted has to be considered. In this thesis we show the utility of algebraic curves over finite fields in public key cryptosystems, specially genus 2 curves, since they offer the minimum key size for a given security level and that significantly reduces the total communication costs of a system, while maintaining a reasonable performance. We analyze how the 2-adic valuation of the cardinality of the Jacobian increases in successive quadratic extensions, considering genus 2 curves with odd characteristic fields, including supersingular curves. In addition, we improve the current algorithms for computing the halving of a divisor of a genus 2 curve over binary fields, which can be useful in scalar multiplication, the main operation in public key cryptography using curves. As regards to privacy, we present a pay-by-phone parking system which enables drivers to pay for public parking while preserving their privacy, and thus impeding the service provider or an attacker to obtain a profile of parking behaviors. Finally, we offer better protocols for smart metering, especially regarding privacy and the avoidance of trusted third parties