An Internet of Things (IoT) engages a large number of resource-constrained edge devices that are internetworked over multi-hop paths. Remote attestation refers to checking the integrity of the software onboard the individual devices (provers) to ensure that it is not maliciously tampered with. Given the scale and the lack of direct communication links, attestation often needs to be conducted over a multi-hop path between a verifier and a prover which raises concern about the integrity and confidentiality of the provided response (digest). To address these issues, this paper proposes PAMA a lightweight attestation protocol utilizing Physical Unclonable Functions (PUFs) to obfuscate the digest and sustain its confidentiality. PAMA does not reveal the actual digest and deprive any node on the dissemination path from even replaying an old attestation response. The response of multiple provers is further aggregated to improve efficiency and scalability while enabling the verifier to authenticate the devices on the path and determine which of them has failed the digest validation if any. PAMA's robustness is rigorously analyzed, and its performance is validated through simulation. The results show that PAMA outperforms competing schemes in terms of runtime complexity, bandwidth efficiency and energy consumption.

Internet of Things (IoT) systems comprise a large number of resource-constrained edge devices that collaborate to serve application tasks. Remote attestation refers to checking the integrity of the software onboard the individual devices to ensure that it is not tampered with or infected by malware. Swarm attestation refers to collective integrity check of multiple devices as a means to cope with the large network size. Yet, existing swarm attestation schemes fall short of identifying the suspected devices and/or achieving important security properties. To fill the technical gap, this paper proposes PISA a lightweight attestation and aggregation framework utilizing Physical Unclonable Functions (PUFs) as the Root-of-Trust in both digest generation and aggregation, within a multi-prover network. The objective is to ensure the privacy and integrity of individual device attestation reports, verifying the authenticity of attestation requests across the network while also identifying the devices that fail the verification. PISA employs a network partitioning algorithm and optimized aggregation paths to amortize overhead and support scalability. The security properties of PISA are rigorously analyzed. The validation results show that PISA outperforms competing schemes, offering enhanced runtime and bandwidth efficiency and reduced energy consumption.

With the increasing popularity of small computing devices and applications of IoT, the need for platform integrity grows both in scale and scope. In particular, the detection of successful attempts to inject a malicious software module or modify an existing one is of utmost importance. This paper promotes LiSB, a novel approach for validating software/firmware integrity and ensuring secure boot-up for resource-constrained embedded devices. LiSB is lightweight, yet very robust. A hardware primitive is used as a Root-of-Trust to support the confidentiality of generated digests and the security of the attestation protocol. Specifically, LiSB employs Physically Unclonable Functions (PUFs) to make the digest device-specific without storing any secrets in the device memory. The performance and robustness of LiSB are validated using a prototype implementation on an FPGA. The results demonstrate that LiSB outperforms recently-published and prominent commercial attestation schemes like TPM, and consumes 25 times less power than SHA-256, which serves as the core component of most existing attestation schemes. The security properties of LiSB are formally analyzed.

Laser Fault Injection Attacks (LFIA) are a major concern in physical security of electronic circuits as they allow an attacker to inject a fault with a very high spatial accuracy. They are also often considered by information technology security evaluation facilities (ITSEFs) to deliver security certification, as Common Criteria, of embedded systems. Time or spatial redundancy can be foreseen as protection methods but they are costly and do not ensure immunity against multiple laser injections. The detection would be efficient if the detecting sensors meet enough density and sensitivity to cover the functional blocks being protected. Most sensors rely on analog and specific technology. In this article, we propose a method to detect LFIAs via a fully digital sensor based on a time to digital converter (TDC) and show its efficacy in detecting such faults in various conditions related to the current induced by the laser, the characteristics of the power grid network (PGN) of the circuit and the environmental variables (voltage, temperature). The simulation results obtained using a 45nm Nangate technology confirms the high efficiency of the proposed scheme in detecting LFIAs in a large range of such conditions.