RADIS: Remote Attestation of Distributed IoT Services

Remote attestation is a security technique through which a remote trusted party (i.e., Verifier) checks the trustworthiness of a potentially untrusted device (i.e., Prover). In the Internet of Things (IoT) systems, the existing remote attestation protocols propose various approaches to detect the modified software and physical tampering attacks. However, in an interoperable IoT system, in which IoT devices interact autonomously among themselves, an additional problem arises: a compromised IoT service can influence the genuine operation of other invoked service, without changing the software of the latter. In this paper, we propose a protocol for Remote Attestation of Distributed IoT Services (RADIS), which verifies the trustworthiness of distributed IoT services. Instead of attesting the complete memory content of the entire interoperable IoT devices, RADIS attests only the services involved in performing a certain functionality. RADIS relies on a control-flow attestation technique to detect IoT services that perform an unexpected operation due to their interactions with a malicious remote service. Our experiments show the effectiveness of our protocol in validating the integrity status of a distributed IoT service.Comment: 21 pages, 10 figures, 2 table

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

ERASMUS: Efficient Remote Attestation via Self- Measurement for Unattended Settings

Remote attestation (RA) is a popular means of detecting malware in embedded and IoT devices. RA is usually realized as an interactive protocol, whereby a trusted party -- verifier -- measures integrity of a potentially compromised remote device -- prover. Early work focused on purely software-based and fully hardware-based techniques, neither of which is ideal for low-end devices. More recent results have yielded hybrid (SW/HW) security architectures comprised of a minimal set of features to support efficient and secure RA on low-end devices. All prior RA techniques require on-demand operation, i.e, RA is performed in real time. We identify some drawbacks of this general approach in the context of unattended devices: First, it fails to detect mobile malware that enters and leaves the prover between successive RA instances. Second, it requires the prover to engage in a potentially expensive (in terms of time and energy) computation, which can be harmful for critical or real-time devices. To address these drawbacks, we introduce the concept of self-measurement where a prover device periodically (and securely) measures and records its own software state, based on a pre-established schedule. A possibly untrusted verifier occasionally collects and verifies these measurements. We present the design of a concrete technique called ERASMUS : Efficient Remote Attestation via Self-Measurement for Unattended Settings, justify its features and evaluate its performance. In the process, we also define a new metric -- Quality of Attestation (QoA). We argue that ERASMUS is well-suited for time-sensitive and/or safety-critical applications that are not served well by on-demand RA. Finally, we show that ERASMUS is a promising stepping stone towards handling attestation of multiple devices (i.e., a group or swarm) with high mobility