Autonomous collaborative networks of devices are rapidly emerging in numerous domains, such as self-driving cars, smart factories, critical infrastructure, and Internet of Things in general. Although autonomy and self-organization are highly desired properties, they increase vulnerability to attacks. Hence, autonomous networks need dependable mechanisms to detect malicious devices in order to prevent compromise of the entire network. However, current mechanisms to detect malicious devices either require a trusted central entity or scale poorly.

A myriad of IoT devices such as bulbs, switches, speakers in a smart home environment allow users to easily control the physical world around them and facilitate their living styles through the sensors already embedded in these devices. Sensor data contains a lot of sensitive information about the user and devices. However, an attacker inside or near a smart home environment can potentially exploit the innate wireless medium used by these devices to exfiltrate sensitive information from the encrypted payload (i.e., sensor data) about the users and their activities, invading user privacy. With this in mind, in this work, we introduce a novel multi-stage privacy attack against user privacy in a smart environment. It is realized utilizing state-of-the-art machine-learning approaches for detecting and identifying the types of IoT devices, their states, and ongoing user activities in a cascading style by only passively sniffing the network traffic from smart home devices and sensors. The attack effectively works on both encrypted and unencrypted communications. We evaluate the efficiency of the attack with real measurements from an extensive set of popular off-the-shelf smart home IoT devices utilizing a set of diverse network protocols like WiFi, ZigBee, and BLE. Our results show that an adversary passively sniffing the traffic can achieve very high accuracy (above 90%) in identifying the state and actions of targeted smart home devices and their users. To protect against this privacy leakage, we also propose a countermeasure based on generating spoofed traffic to hide the device states and demonstrate that it provides better protection than existing solutions.

Unlike traditional processors, embedded Internet of Things (IoT) devices lack resources to incorporate protection against modern sophisticated attacks resulting in critical consequences. Remote attestation (RA) is a security service to establish trust in the integrity of a remote device. While conventional RA is static and limited to detecting malicious modification to software binaries at load-time, recent research has made progress towards runtime attestation, such as attesting the control flow of an executing program. However, existing control-flow attestation schemes are inefficient and vulnerable to sophisticated data-oriented programming (DOP) attacks subvert these schemes and keep the control flow of the code intact. In this paper, we present LiteHAX, an efficient hardware-assisted remote attestation scheme for RISC-based embedded devices that enables detecting both control-flow attacks as well as DOP attacks. LiteHAX continuously tracks both the control-flow and data-flow events of a program executing on a remote device and reports them to a trusted verifying party. We implemented and evaluated LiteHAX on a RISC-V System-on-Chip (SoC) and show that it has minimal performance and area overhead.

Remote attestation is a crucial security service particularly relevant to increasingly popular IoT (and other embedded) devices. It allows a trusted party (verifier) to learn the state of a remote, and potentially malware-infected, device (prover). Most existing approaches are static in nature and only check whether benign software is initially loaded on the prover. However, they are vulnerable to runtime attacks that hijack the application's control or data flow, e.g., via return-oriented programming or data-oriented exploits. As a concrete step towards more comprehensive runtime remote attestation, we present the design and implementation of Control-FLow ATtestation (C-FLAT) that enables remote attestation of an application's control-flow path, without requiring the source code. We describe a full prototype implementation of C-FLAT on Raspberry Pi using its ARM TrustZone hardware security extensions. We evaluate C-FLAT's performance using a real-world embedded (cyber-physical) application, and demonstrate its efficacy against control-flow hijacking attacks.

The emerging and much-touted Internet of Things (IoT) presents a variety of security and privacy challenges. Prominent among them is the establishment of trust in remote IoT devices, which is typically attained via remote attestation, a distinct security service that aims to ascertain the current state of a potentially compromised remote device. Remote attestation ranges from relatively heavy-weight secure hardware-based techniques, to light-weight software-based ones, and also includes approaches that blend software (e.g., control-flow integrity) and hardware features (e.g., PUFs). In this paper, we survey the landscape of state-of-the-art attestation techniques from the IoT device perspective and argue that most of them have a role to play in IoT trust establishment.