Automotive firmware extraction and analysis techniques

An intricate network of embedded devices, called Electronic Control Units (ECUs), is responsible for the functionality of a modern vehicle. Every module processes a myriad of information and forwards it on to other nodes on the network, typically an automotive bus such as the Controller Area Network (CAN). Analysing embedded device software, and automotive in particular, brings many challenges. The analyst must, especially in the notoriously secretive automotive industry, first lift the ECU firmware from the hardware, which typically prevents unauthorised access. In this thesis, we address this problem in two ways: - We detail and bypass the access control mechanism used in diagnostic protocols in ECU firmware. Using existing diagnostic functionality, we present a generic technique to download code to RAM and execute it, without requiring physical access to the ECU. We propose a generic firmware readout framework on top of this, which only requires access to the CAN bus. - We analyse various embedded bootloaders and combine dynamic analysis with low-level hardware fault attacks, resulting in several fault-injection attacks which bypass on-chip readout protection. We then apply these firmware extraction techniques to acquire immobiliser firmware by two different manufacturers, from which we reverse engineer the DST80 cipher and present it in full detail here. Furthermore, we point out flaws in the key generation procedure, also recovered from the ECU firmware, leading to a full key recovery based on publicly readable transponder pages

PrivateDrop: Practical Privacy-Preserving Authentication for Apple AirDrop

Apple's offline file-sharing service AirDrop is integrated into more than 1.5 billion end-user devices worldwide. We discovered two design flaws in the underlying protocol that allow attackers to learn the phone numbers and email addresses of both sender and receiver devices. As a remediation, we study the applicability of private set intersection (PSI) to mutual authentication, which is similar to contact discovery in mobile messengers. We propose a novel optimized PSI-based protocol called PrivateDrop that addresses the specific challenges of offline resource-constrained operation and integrates seamlessly into the current AirDrop protocol stack. Using our native PrivateDrop implementation for iOS and macOS, we experimentally demonstrate that PrivateDrop preserves AirDrop's exemplary user experience with an authentication delay well below one second. We responsibly disclosed our findings to Apple and open-sourced our PrivateDrop implementation

Efficient and Secure Implementations of Lightweight Symmetric Cryptographic Primitives

This thesis is devoted to efficient and secure implementations of lightweight symmetric cryptographic primitives for resource-constrained devices such as wireless sensors and actuators that are typically deployed in remote locations. In this setting, cryptographic algorithms must consume few computational resources and withstand a large variety of attacks, including side-channel attacks. The first part of this thesis is concerned with efficient software implementations of lightweight symmetric algorithms on 8, 16, and 32-bit microcontrollers. A first contribution of this part is the development of FELICS, an open-source benchmarking framework that facilitates the extraction of comparative performance figures from implementations of lightweight ciphers. Using FELICS, we conducted a fair evaluation of the implementation properties of 19 lightweight block ciphers in the context of two different usage scenarios, which are representatives for common security services in the Internet of Things (IoT). This study gives new insights into the link between the structure of a cryptographic algorithm and the performance it can achieve on embedded microcontrollers. Then, we present the SPARX family of lightweight ciphers and describe the impact of software efficiency in the process of shaping three instances of the family. Finally, we evaluate the cost of the main building blocks of symmetric algorithms to determine which are the most efficient ones. The contributions of this part are particularly valuable for designers of lightweight ciphers, software and security engineers, as well as standardization organizations. In the second part of this work, we focus on side-channel attacks that exploit the power consumption or the electromagnetic emanations of embedded devices executing unprotected implementations of lightweight algorithms. First, we evaluate different selection functions in the context of Correlation Power Analysis (CPA) to infer which operations are easy to attack. Second, we show that most implementations of the AES present in popular open-source cryptographic libraries are vulnerable to side-channel attacks such as CPA, even in a network protocol scenario where the attacker has limited control of the input. Moreover, we describe an optimal algorithm for recovery of the master key using CPA attacks. Third, we perform the first electromagnetic vulnerability analysis of Thread, a networking stack designed to facilitate secure communication between IoT devices. The third part of this thesis lies in the area of side-channel countermeasures against power and electromagnetic analysis attacks. We study efficient and secure expressions that compute simple bitwise functions on Boolean shares. To this end, we describe an algorithm for efficient search of expressions that have an optimal cost in number of elementary operations. Then, we introduce optimal expressions for first-order Boolean masking of bitwise AND and OR operations. Finally, we analyze the performance of three lightweight block ciphers protected using the optimal expressions

Security is an Architectural Design Constraint

In state-of-the-art design paradigm, time, space and power efficiency are considered the primary design constraints. Quite often, this approach adversely impacts the security of the overall system, especially when security is adopted as a countermeasure after some vulnerability is identified. In this position paper, we motivate the idea that security should also be considered as an architectural design constraint in addition to time, space and power. We show that security and efficiency objectives along the three design axes of time, space and power are in fact tightly coupled while identifying that security stands in direct contrast with them across all layers of architectural design. We attempt to prove our case utilizing a proof-by-evidence approach wherein we refer to various works across literature that explicitly imply the eternal conflict between security and efficiency. Thus, security has to be treated as a design constraint from the very beginning. Additionally, we advocate a security-aware design flow starting from the choice of cryptographic primitives, protocols and system design

Sensor-based ICT Systems for Smart Societies

L'abstract è presente nell'allegato / the abstract is in the attachmen

Sécurité et protection de la vie privée dans les systèmes embarqués automobiles

Electronic equipment has become an integral part of a vehicle's network architecture, which consists of multiple buses and microcontrollers called Electronic Control Units (ECUs). These ECUs recently also connect to the outside world. Navigation and entertainment system, consumer devices, and Car2X functions are examples for this. Recent security analyses have shown severe vulnerabilities of exposed ECUs and protocols, which may make it possible for attackers to gain control over a vehicle. Given that car safety-critical systems can no longer be fully isolated from such third party devices and infotainment services, we propose a new approach to securing vehicular on-board systems that combines mechanisms at different layers of the communication stack and of the execution platforms. We describe our secure communication protocols, which are designed to provide strong cryptographic assurances together with an efficient implementation fitting the prevalent vehicular communication paradigms. They rely on hardware security modules providing secure storage and acting as root of trust. A distributed data flow tracking based approach is employed for checking code execution against a security policy describing authorized communication patterns. Binary instrumentation is used to track data flows throughout execution (taint engine) and also between control units (middleware), thus making it applicable to industrial applications. We evaluate the feasibility of our mechanisms to secure communication on the CAN bus, which is ubiquitously implemented in cars today. A proof of concept demonstrator also shows the feasibility of integrating security features into real vehicles.L'équipement électronique de bord est maintenant devenue partie intégrante de l'architecture réseau des véhicules. Elle s’appuie sur l'interconnexion de microcontroleurs appelés ECUs par des bus divers. On commence maintenant à connecter ces ECUs au monde extérieur, comme le montrent les systèmes de navigation, de divertissement, ou de communication mobile embarqués, et les fonctionnalités Car2X. Des analyses récentes ont montré de graves vulnérabilités des ECUs et protocoles employés qui permettent à un attaquant de prendre le contrôle du véhicule. Comme les systèmes critiques du véhicule ne peuvent plus être complètement isolés, nous proposons une nouvelle approche pour sécuriser l'informatique embarquée combinant des mécanismes à différents niveaux de la pile protocolaire comme des environnements d'exécution. Nous décrivons nos protocoles sécurisés qui s'appuient sur une cryptographie efficace et intégrée au paradigme de communication dominant dans l'automobile et sur des modules de sécurité matériels fournissant un stockage sécurisé et un noyau de confiance. Nous décrivons aussi comment surveiller les flux d'information distribués dans le véhicule pour assurer une exécution conforme à la politique de sécurité des communications. L'instrumentation binaire du code, nécessaire pour l’industrialisation, est utilisée pour réaliser cette surveillance durant l’exécution (par data tainting) et entre ECUs (dans l’intergiciel). Nous évaluons la faisabilité de nos mécanismes pour sécuriser la communication sur le bus CAN aujourd'hui omniprésent dans les véhicules. Une preuve de concept montre aussi la faisabilité d'intégrer des mécanismes de sécurité dans des véhicules réels

Sustainable Trusted Computing: A Novel Approach for a Flexible and Secure Update of Cryptographic Engines on a Trusted Platform Module

Trusted computing is gaining an increasing acceptance in the industry and finding its way to cloud computing. With this penetration, the question arises whether the concept of hardwired security modules will cope with the increasing sophistication and security requirements of future IT systems and the ever expanding threats and violations. So far, embedding cryptographic hardware engines into the Trusted Platform Module (TPM) has been regarded as a security feature. However, new developments in cryptanalysis, side-channel analysis, and the emergence of novel powerful computing systems, such as quantum computers, can render this approach useless. Given that, the question arises: Do we have to throw away all TPMs and lose the data protected by them, if someday a cryptographic engine on the TPM becomes insecure? To address this question, we present a novel architecture called Sustainable Trusted Platform Module (STPM), which guarantees a secure update of the TPM cryptographic engines without compromising the system’s trustworthiness. The STPM architecture has been implemented as a proof-of-concept on top of a Xilinx Virtex-5 FPGA platform, demonstrating the test cases with an update of the fundamental hash and asymmetric engines of the TPM

Internet of Things From Hype to Reality

The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions