Detecting malicious encrypted traffic with privacy set intersection in cloud-assisted industrial internet

Encryption technology provides the ability of confidential transmission to ensure the security of Industrial Internet communication, but it makes detecting malicious encrypted traffic very difficult. To resolve the conflict between the difficulty of malicious encrypted traffic detection and the requirements of traffic privacy protection, we propose a cloud-assisted Industrial Internet malicious encrypted traffic detection scheme with privacy protection. To accurately match the encrypted traffic and the detection rules, a privacy set intersection protocol based on the oblivious pseudorandom function and random garbled Bloom filter is constructed, which can detect malicious traffic without revealing data content. Meanwhile, our scheme can allow semi-trusted cloud servers to assist resource-constrained end devices to participate in private calculations. The key-homomorphic encryption is introduced to obfuscate the detection rules, making the detection rules always transparent to end users and semi-trusted cloud servers. We also design the random input verification to make the malicious end users do not have any opportunity to participate in the privacy set intersection calculation using arbitrary data. The scheme analysis and performance evaluation results show that our scheme can effectively guarantee the security of encrypted traffic detection with better detection performance and limited resource consumption.