PADS: Practical Attestation for Highly Dynamic Swarm Topologies

Remote attestation protocols are widely used to detect device configuration (e.g., software and/or data) compromise in Internet of Things (IoT) scenarios. Unfortunately, the performances of such protocols are unsatisfactory when dealing with thousands of smart devices. Recently, researchers are focusing on addressing this limitation. The approach is to run attestation in a collective way, with the goal of reducing computation and communication. Despite these advances, current solutions for attestation are still unsatisfactory because of their complex management and strict assumptions concerning the topology (e.g., being time invariant or maintaining a fixed topology). In this paper, we propose PADS, a secure, efficient, and practical protocol for attesting potentially large networks of smart devices with unstructured or dynamic topologies. PADS builds upon the recent concept of non-interactive attestation, by reducing the collective attestation problem into a minimum consensus one. We compare PADS with a state-of-the art collective attestation protocol and validate it by using realistic simulations that show practicality and efficiency. The results confirm the suitability of PADS for low-end devices, and highly unstructured networks.Comment: Submitted to ESORICS 201

ScaRR: Scalable Runtime Remote Attestation for Complex Systems

The introduction of remote attestation (RA) schemes has allowed academia and industry to enhance the security of their systems. The commercial products currently available enable only the validation of static properties, such as applications fingerprint, and do not handle runtime properties, such as control-flow correctness. This limitation pushed researchers towards the identification of new approaches, called runtime RA. However, those mainly work on embedded devices, which share very few common features with complex systems, such as virtual machines in a cloud. A naive deployment of runtime RA schemes for embedded devices on complex systems faces scalability problems, such as the representation of complex control-flows or slow verification phase. In this work, we present ScaRR: the first Scalable Runtime Remote attestation schema for complex systems. Thanks to its novel control-flow model, ScaRR enables the deployment of runtime RA on any application regardless of its complexity, by also achieving good performance. We implemented ScaRR and tested it on the benchmark suite SPEC CPU 2017. We show that ScaRR can validate on average 2M control-flow events per second, definitely outperforming existing solutions.Comment: 14 page

Remote attestation to ensure the security of future Internet of Things services

The Internet of Things (IoT) evolution is gradually reshaping the physical world into smart environments that involve a large number of interconnected resource-constrained devices which collect, process, and exchange enormous amount of (more or less) sensitive information. With the increasing number of interconnected IoT devices and their capabilities to control the environment, IoT systems are becoming a prominent target of sophisticated cyberattacks. To deal with the expanding attack surface, IoT systems require adequate security mechanisms to verify the reliability of IoT devices. Remote attestation protocols have recently gained wide attention in IoT systems as valuable security mechanisms that detect the adversarial presence and guarantee the legitimate state of IoT devices. Various attestation schemes have been proposed to optimize the effectiveness and efficiency of remote attestation protocols of a single IoT device or a group of IoT devices. Nevertheless, some cyber attacks remain undetected by current attestation methods, and attestation protocols still introduce non-negligible computational overheads for resource-constrained devices. This thesis presents the following new contributions in the area of remote attestation protocols that verify the trustworthiness of IoT devices. First, this thesis shows the limitations of existing attestation protocols against runtime attacks which, by compromising a device, may maliciously influence the operation of other genuine devices that interact with the compromised one. To detect such an attack, this thesis introduces the service perspective in remote attestation and presents a synchronous remote attestation protocol for distributed IoT services. Second, this thesis designs, implements and evaluates a novel remote attestation scheme that releases the constraint of synchronous interaction between devices and enables the attestation of asynchronous distributed IoT services. The proposed scheme also attests asynchronously a group of IoT devices, without interrupting the regular operations of all the devices at the same time. Third, this thesis proposes a new approach that aims to reduce the interruption time of the regular work that remote attestation introduces in an IoT device. This approach intends to decrease the computational overhead of attestation by allowing an IoT device to securely offload the attestation process to a cloud service, which then performs attestation independently on the cloud, on behalf of the IoT device

KALwEN: a new practical and interoperable key management scheme for body sensor networks

Key management is the pillar of a security architecture. Body sensor networks (BSNs) pose several challenges–some inherited from wireless sensor networks (WSNs), some unique to themselves–that require a new key management scheme to be tailor-made. The challenge is taken on, and the result is KALwEN, a new parameterized key management scheme that combines the best-suited cryptographic techniques in a seamless framework. KALwEN is user-friendly in the sense that it requires no expert knowledge of a user, and instead only requires a user to follow a simple set of instructions when bootstrapping or extending a network. One of KALwEN's key features is that it allows sensor devices from different manufacturers, which expectedly do not have any pre-shared secret, to establish secure communications with each other. KALwEN is decentralized, such that it does not rely on the availability of a local processing unit (LPU). KALwEN supports secure global broadcast, local broadcast, and local (neighbor-to-neighbor) unicast, while preserving past key secrecy and future key secrecy (FKS). The fact that the cryptographic protocols of KALwEN have been formally verified also makes a convincing case. With both formal verification and experimental evaluation, our results should appeal to theorists and practitioners alike

KALwEN: A New Practical and Interoperable Key Management Scheme for Body Sensor Networks

Key management is the pillar of a security architecture. Body sensor networks(BSNs) pose several challenges -- some inherited from wireless sensor networks(WSNs), some unique to themselves -- that require a new key management scheme to be tailor-made. The challenge is taken on, and the result is KALwEN, a new lightweight scheme that combines the best-suited cryptographic techniques in a seamless framework. KALwEN is user-friendly in the sense that it requires no expert knowledge of a user, and instead only requires a user to follow a simple set of instructions when bootstrapping or extending a network. One of KALwEN's key features is that it allows sensor devices from different manufacturers, which expectedly do not have any pre-shared secret, to establish secure communications with each other. KALwEN is decentralized, such that it does not rely on the availability of a local processing unit (LPU). KALwEN supports global broadcast, local broadcast and neighbor-to-neighbor unicast, while preserving past key secrecry and future key secrecy. The fact that the cryptographic protocols of KALwEN have been formally verified also makes a convincing case