Confidentiality attacks against encrypted control systems
Amir Mohammad Naseri, Walter Lúcia, Amr Youssef · Cyber-Physical Systems · 2022
Encrypted control systems were introduced to enhance the security of cyber-physical systems, which outsource control action computations to a third-party platform. To protect the confidentiality of the transmitted data, homomorphic encryption schemes are particularly appealing for their capability of allowing computations on encrypted data. By considering the popular ElGamal and Paillier encryption schemes, this paper shows that encrypted control systems are vulnerable to attackers leveraging the inherently small domains of the plaintext data in control systems and the randomisation process required to make the utilised ciphers semantically secure. Finally, we present some countermeasures to defend against these attacks.