HEALED - HEaling & Attestation for Low-End Embedded Devices.

We are increasingly surrounded by numerous embedded systems which collect, exchange, and process sensitive and safety-critical information. The Internet of Things (IoT) allows a large number of interconnected devices to be accessed and controlled remotely, across existing network infrastructure. Consequently, a remote attacker can exploit security vulnerabilities and compromise these systems. In this context, remote attestation is a very useful security service that allows to remotely and securely verify the integrity of devices' software state, thus allowing the detection of potential malware on the device. However, current attestation schemes focus on detecting whether a device is infected by malware but not on disinfecting it and restoring its software to a benign state. In this paper we present HEALED - the first remote attestation scheme for embedded devices that allows both detection of software compromise and disinfection of compromised devices. HEALED uses Merkle Hash Trees (MHTs) for measurement of software state, which allows restoring a device to a benign state in a secure and efficient manner.