Hardware-assisted Remote Runtime Attestation for Critical Embedded Systems

Abstract

Remote attestation, as a challenge-response protocol, enables a trusted entity, called verifier, to ask for an untrusted device, called prover, to provide assurance about its internal integrity. With its strong guarantees not suffering from false positives, remote attestation is becoming increasingly popular for critical embedded systems which can be used for medical, military or industrial control purposes. Previous proposals, which used checksums on static code regions to assure the load-time integrity, miss the runtime attacks that affect only dynamic memory regions. To address these attacks, this paper proposes a new scheme that attests the runtime integrity according to the control and data features of the program. The runtime check is performed in real time with the help of a novel hardware security module (HSM) which is connected to the prover's system bus. Proposed HSM detects runtime issues by checking compliance of the bits seen on the address and data bus with the static model loaded into its memory. Our attestation scheme can detect sophisticated runtime attacks such as code-reuse and non-control data attacks.

Strategic Remote Attestation: Testbed for Internet-of-Things Devices and Stackelberg Security Game for Optimal Strategies

“…The works led to later works in terms of cell-and block-based pseudo-random checksum, respectively. A few recent works include hardware-assisted remote runtime attestation [8] that addresses runtime attack detection, a low-cost checksum-based remote memory attestation for smart grid [21], lightweight remote attestation in distributed wireless sensor networks where all nodes validate each other's data [9], and so on. Survey papers on attestation, for example, Steiner et al presented a more comprehensive overview on checksum-based attestation [16].…”

TRUVIN: Lightweight Detection of Data Oriented Attacks Through Trusted Value Integrity

“…Even though benchmark experiments have never identified those structures as critical entirely, in such a case, we suggest using checksums to digest consecutive elements of composite variables (e.g. URL) similar to the previous work [12].…”

Practical Verifiable Computation by Using a Hardware-Based Correct Execution Environment

“…Is it enough if the computing platform guarantees the integrity of the input and function? The remote attestation technique [19]- [21], [26] can be used to verify such integrity, as well as the integrity of the control flow. When remote attestation is used for embedded systems, the entire memory space can be verified (even though it is still challenging, because of dynamic memory regions), but, for servers, this is not feasible.…”

“…Existing trusted hardware approaches can be classified into hardware-based root-of-trust [17], [18], attestation [19]- [21], and isolation [22]- [24]. In the hardware-based root-of-trust approaches [17], [18], the security of a system is enhanced by building the system based on the invariants guaranteed by dedicated hardware.…”

“…For example, the private key stored in Trusted Platform Module (TPM) [18] can be used to authenticate software running on the system. The attestation techniques [19]- [21], [23], [26]- [28] are used to validate the integrity of a program, its execution (control flow integrity), and/or data integrity. The isolation approaches [22]- [24] provide a hardware mechanism to segregate system resources from potentially malicious programs.…”