VISE: Combining Intel SGX and Homomorphic Encryption for Cloud Industrial Control Systems

• Published in: IEEE transactions on computers Vol. 70; no. 5; pp. 711 - 724
• Main Authors: Coppolino, Luigi, D'Antonio, Salvatore, Formicola, Valerio, Mazzeo, Giovanni, Romano, Luigi
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Cloud computing; cloud security; Containers; Control systems; Cryptography; Data processing; Encryption; homomorphic encryption; Industrial control; industrial control systems; Industrial electronics; Integrated circuits; Intel SGX; Monitoring; Security; Sensors; Servers; Trusted computing
• ISSN: 0018-9340; 1557-9956
• DOI: 10.1109/TC.2020.2995638

Protecting data-in-use from privileged attackers is challenging. New CPU extensions (notably: Intel SGX ) and cryptographic techniques (specifically: Homomorphic Encryption ) can guarantee privacy even in untrusted third-party systems. HE allows sensitive processing on ciphered data. However, it is affected by i) a dramatic ciphertext expansion making HE unusable when bandwidth is narrow, ii) unverifiable conditional variables requiring off-premises support. Intel SGX allows sensitive processing in a secure enclave. Unfortunately, it is i) strictly bonded to the hosting server making SGX unusable when the live migration of cloud VMs/Containers is desirable, ii) limited in terms of usable memory, which is in contrast with resource-consuming data processing. In this article, we propose the VIrtual Secure Enclave (VISE) , an approach that effectively combines the two aforementioned techniques, to overcome their limitations and ultimately make them usable in a typical cloud setup. VISE moves the execution of sensitive HE primitives (e.g., encryption) to the cloud in a remotely attested SGX enclave, and then performs sensitive processing on HE data-outside the enclave-leveraging all the memory resources available. We demonstrate that VISE meets the challenging security and performance requirements of a substantial application in the Industrial Control Systems domain. Our experiments prove the practicability of the proposed solution.