Automated Proof for Authorization Protocols of TPM 2.0 in Computational Model (full version)

We present the first automated proof of the authorization protocols in TPM 2.0 in the computational model. The Trusted Platform Module(TPM) is a chip that enables trust in computing platforms and achieves more security than software alone. The TPM interacts with a caller via a predefined set of commands. Many commands reference TPM-resident structures, and use of them may require authorization. The TPM will provide an acknowledgement once receiving an authorization. This interact ensure the authentication of TPM and the caller. In this paper, we present a computationally sound mechanized proof for authorization protocols in the TPM 2.0. We model the authorization protocols using a probabilistic polynomial-time calculus and prove authentication between the TPM and the caller with the aid of the tool CryptoVerif, which works in the computational model. In addition, the prover gives the upper bounds to break the authentication between them

An Attestation Architecture for Blockchain Networks

If blockchain networks are to become the building blocks of the infrastructure for the future digital economy, then several challenges related to the resiliency and survivability of blockchain networks need to be addressed. The survivability of a blockchain network is influenced by the diversity of its nodes. Trustworthy device-level attestations permits nodes in a blockchain network to provide truthful evidence regarding their current configuration, operational state, keying material and other system attributes. In the current work we review the recent developments towards a standard attestation architecture and evidence conveyance protocols. We explore the applicability and benefits of a standard attestation architecture to blockchain networks. Finally, we discuss a number of open challenges related to node attestations that has arisen due to changing model of blockchain network deployments, such as the use virtualization and containerization technologies for nodes in cloud infrastructures.Comment: 33 pages, 10 figure

Security and Trust in Safety Critical Infrastructures

Critical infrastructures such as road vehicles and railways are undergoing a major change, which increases the dependency of their operation and control on Information Technology (IT) and makes them more vulnerable to malicious intent. New complex communication infrastructures emerge using the increased connectivity of these safety-critical systems to enable efficient management of operational processes, service provisioning, and information exchange for various (third-party) actors. Railway Command and Control Systems (CCSs) turn with the introduction of digital interlocking into an “Internet of Railway Things”, where safety-critical railway signaling components are deployed on common-purpose platforms and connected via standard IP-based networks. Similarly, the mass adoption of Electric Vehicles (EVs) and the need to supply their batteries with energy for charging has given rise to a Vehicle-to-Grid (V2G) infrastructure, which connects vehicles to power grids and multiple service providers to coordinate charging and discharging processes and maintain grid stability under varying power demands. The Plug-and-Charge feature brought in by the V2G communication standard ISO 15118 allows an EV to access charging and value-added services, negotiate charging schedules, and support the grid as a distributed energy resource in a largely automated way, by leveraging identity credentials installed in the vehicle for authentication and payment. The fast deployment of this advanced functionality is driven by economical and political decisions including the EU Green Deal for climate neutrality. Due to the complex requirements and long standardization and development cycles, the standards and regulations, which play the key role in operating and protecting critical infrastructures, are under pressure to enable the timely and cost-effective adoption. In this thesis, we investigate security and safety of future V2G and railway command and control systems with respect to secure communication, platform assurance as well as safety and security co-engineering. One of the major goals in this context is the continuous collaboration and establishment of the proposed security solutions in upcoming domain-specific standards, thus ensuring their practical applicability and prompt implementation in real-world products. We first analyze the security of V2G communication protocols and requirements for secure service provisioning via charging connections. We propose a new Plug-and-Patch protocol that enables secure update of EVs as a value-added service integrated into the V2G charging loop. Since EVs can also participate in energy trading by storing and feeding previously stored energy to grid, home, or other vehicles, we then investigate fraud detection methods that can be employed to identify manipulations and misbehaving users. In order to provide a strong security foundation for V2G communications, we propose and analyze three security architectures employing a hardware trust anchor to enable trust establishment in V2G communications. We integrate these architectures into standard V2G protocols for load management, e-mobility services and value-added services in the V2G infrastructure, and evaluate the associated performance and security trade-offs. The final aspect of this work is safety and security co-engineering, i.e., integration of safety and security processes vital for the adequate protection of connected safety-critical systems. We consider two application scenarios, Electric Vehicle Charging System (EVCS) and Object Controller (OC) in railway CCS, and investigate how security methods like trusted computing can be applied to provide both required safety and security properties. In the case of EVCS, we bind the trust boundary for safety functionality (certified configuration) to the trust boundary in the security domain and design a new security architecture that enforces safety properties via security assertions. For the railway use case, we focus on ensuring non-interference (separation) between these two domains and develop a security architecture that allows secure co-existence of applications with different criticality on the same hardware platform. The proposed solutions have been presented to the committee ISO/TC 22/SC 31/JWG 1 that develops the ISO 15118 standard series and to the DKE working group “Informationssicherheit für Elektromobilität” responsible for the respective application guidelines. Our security extension has been integrated in the newest edition ISO 15118-20 released in April 2022. Several manufacturers have already started concept validation for their future products using our results. In this way, the presented analyses and techniques are fundamental contributions in improving the state of security for e-mobility and railway applications, and the overall resilience of safety-critical infrastructures to malicious attacks

QuantumCharge: Post-Quantum Cryptography for Electric Vehicle Charging

ISO 15118 enables charging and billing of Electric Vehicles (EVs) without user interaction by using locally installed cryptographic credentials that must be secure over the long lifetime of vehicles. In the dawn of quantum computers, Post-Quantum Cryptography (PQC) needs to be integrated into the EV charging infrastructure. In this paper, we propose QuantumCharge, a PQC extension for ISO 15118, which includes concepts for migration, crypto-agility, verifiable security, and the use of PQC-enabled hardware security modules. Our prototypical implementation and the practical evaluation demonstrate the feasibility, and our formal analysis shows the security of QuantumCharge, which thus paves the way for secure EV charging infrastructures of the future

Union, intersection, and refinement types and reasoning about type disjointness for security protocol analysis

In this thesis we present two new type systems for verifying the security of cryptographic protocol models expressed in a spi-calculus and, respectively, of protocol implementations expressed in a concurrent lambda calculus. In this thesis we present two new type systems for verifying the security of cryptographic protocol models expressed in a spi-calculus and, respectively, of protocol implementations expressed in a concurrent lambda calculus. The two type systems combine prior work on refinement types with union and intersection types and with the novel ability to reason statically about the disjointness of types. The increased expressivity enables the analysis of important protocol classes that were previously out of scope for the type-based analyses of cryptographic protocols. In particular, our type systems can statically analyze protocols that are based on zero-knowledge proofs, even in scenarios when certain protocol participants are compromised. The analysis is scalable and provides security proofs for an unbounded number of protocol executions. The two type systems come with mechanized proofs of correctness and efficient implementations.In dieser Arbeit werden zwei neue Typsysteme vorgestellt, mit denen die Sicherheit kryptographischer Protokolle, modelliert in einem spi-Kalkül, und Protokollimplementierungen, beschrieben in einem nebenläufigen Lambdakalkül, verifiziert werden kann. Die beiden Typsysteme verbinden vorausgehende Arbeiten zu Verfeinerungstypen mit disjunktiven und konjunktiven Typen, und ermöglichen außerdem, statisch zu folgern, dass zwei Typen disjunkt sind. Die Ausdrucksstärke der Systeme erlaubt die Analyse wichtiger Klassen von Protokollen, die bisher nicht durch typbasierte Protokollanalysen behandelt werden konnten. Insbesondere ist mit den vorgestellten Typsystemen auch die statische Analyse von Protokollen möglich, die auf Zero-Knowledge-Beweisen basieren, selbst unter der Annahme, dass einige Protokollteilnehmer korrumpiert sind. Die Analysetechnik skaliert und erlaubt Sicherheitsbeweise für eine unbeschränkte Anzahl von Protokollausführungen. Die beiden Typsysteme sind formal korrekt bewiesen und effizient implementiert

Engineering Trustworthy Systems by Minimizing and Strengthening their TCBs using Trusted Computing

The Trusted Computing Base (TCB) describes the part of an IT system that is responsible for enforcing a certain security property of the system. In order to engineer a trustworthy system, the TCB must be as secure as possible. This can be achieved by reducing the number, size and complexity of components that are part of the TCB and by using hardened components as part of the TCB. Worst case scenario is for the TCB to span the complete IT system. Best case is for the TCB to be reduced to only a strengthened Root of Trust such as a Hardware Security Module (HSM). One such very secure HSMs with many capabilities is the Trusted Platform Module (TPM). This thesis demonstrates how the TCB of a system can be largely or even solely reduced to the TPM for a variety of security policies, especially in the embedded domain. The examined scenarios include the policies for securing of device resident data at rest also during firmware updates, the enforcement of firmware product lines at runtime, the securing of payment credentials in Plug and Charge controllers, the recording of audit trails over attestation data and a very generic role-based access management. In order to allow evaluating these different solutions, the notion of a dynamic lifecycle dimension for a TCB is introduced. Furthermore, an approach towards engineering such systems based on a formal framework is presented. These scenarios provide evidence for the potential to enforce even complex security policies in small and thus strong TCBs. The approach for implementing those policies can often be inspired by a formal methods based engineering process or by means of additive functional engineering, where a base system is expanded by increased functionality in each step. In either case, a trustworthy system with high assurance capabilities can be achieved

Trusted GNSS-Based Time Synchronization for Industry 4.0 Applications

The protection of satellite-derived timing information is becoming a fundamental requirement in Industry 4.0 applications, as well as in a growing number of critical infrastructures. All the industrial systems where several nodes or devices communicate and/or coordinate their functionalities by means of a communication network need accurate, reliable and trusted time synchronization. For instance, the correct operation of automation and control systems, measurement and automatic test systems, power generation, transmission, and distribution typically require a sub-microsecond time accuracy. This paper analyses the main attack vectors and stresses the need for software integrity control at network nodes of Industry 4.0 applications to complement existing security solutions that focus on Global Navigation Satellite System (GNSS) radio-frequency spectrum and Precision Time Protocol (PTP), also known as IEEE-1588. A real implementation of a Software Integrity Architecture in accordance with Trusted Computing principles concludes the work, together with the presentation of promising results obtained with a flexible and reconfigurable testbed for hands-on activities

FORMALLY ANALYZING AND VERIFYING SECURE SYSTEM DESIGN AND IMPLEMENTATION

Ph.DDOCTOR OF PHILOSOPH