A Network Intrusion Protection System (NIPS) analyzes and blocks HTTPS-encrypted traffic using several techniques, despite the encryption making direct content inspection difficult. Here's how it works:
TLS/SSL Interception (SSL/TLS Decryption)
The NIPS can act as a man-in-the-middle (MITM) proxy to decrypt HTTPS traffic for inspection. It terminates the TLS connection from the client, inspects the traffic, and then re-encrypts it before forwarding it to the destination server. This requires deploying a trusted certificate on clients to avoid browser warnings.
Example: A NIPS decrypts HTTPS traffic to detect malware downloads or command-and-control (C2) communications in encrypted sessions.
Certificate Pinning Bypass & Anomaly Detection
Even without full decryption, the NIPS can analyze metadata (e.g., IP addresses, domain names, packet sizes, and TLS handshake patterns) to identify suspicious behavior. For example, it can flag connections to known malicious domains or unusual TLS versions.
Example: Blocking a connection to a domain associated with phishing, even if the content is encrypted.
Machine Learning & Behavioral Analysis
Advanced NIPS use machine learning to detect anomalies in encrypted traffic patterns, such as unusual data volumes or connection frequencies, which may indicate attacks like data exfiltration.
Example: Detecting a sudden spike in encrypted traffic from a server, suggesting potential data theft.
Signature-Based Detection
The NIPS can match known attack signatures (e.g., exploit payloads) against decrypted traffic or metadata.
Example: Blocking an HTTPS request containing a known SQL injection payload after decryption.
Recommended Tencent Cloud Service:
For HTTPS traffic inspection and protection, Tencent Cloud Web Application Firewall (WAF) and Tencent Cloud Anti-DDoS Advanced provide encrypted traffic analysis, DDoS protection, and threat detection. Additionally, Tencent Cloud Private Network (VPC) with security groups and network ACLs can enforce encrypted traffic policies. For deep inspection, Tencent Cloud Security Center integrates with decryption solutions to monitor encrypted threats.
Note: Proper certificate management and compliance with privacy regulations are essential when using decryption techniques.