Encrypted Traffic Analysis via Contextual Data Classification

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Solution Overview

Problem

The increasing amount of encrypted network traffic poses challenges for security systems, as existing technologies like deep packet inspection are inapplicable to encrypted traffic, making it difficult to detect malicious activities such as malware and data exfiltration.

Innovation Solution

A device in a network captures contextual traffic data from unencrypted packets associated with encrypted traffic flows and uses a machine learning-based classifier to analyze and classify the encrypted traffic, generating alerts based on the classification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deep packet inspection is used to detect malicious traffic, then detection accuracy is improved, but it becomes inapplicable to encrypted traffic

Engineering Contradiction:
Improvedetection accuracyVSAvoidapplicability to encrypted traffic
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces contextual traffic data as an intermediary element that mediates between the encrypted traffic (which cannot be inspected) and the detection system. By capturing unencrypted packets from the same client device and analyzing their characteristics, the system creates a proxy representation of the client's behavior that can be inspected without decrypting the actual encrypted traffic, thus resolving the contradiction between maintaining detection accuracy and handling encrypted traffic.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If encrypted traffic is used to protect data, then security is improved, but malicious activities become undetectable

Engineering Contradiction:
Improvedata protectionVSAvoiddetectability of malicious activities
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The system establishes a feedback loop by capturing contextual traffic data from client devices, analyzing it through machine learning classifiers, and using the results to detect malicious encrypted traffic. The contextual data serves as feedback about client behavior patterns, allowing the system to infer the nature of encrypted traffic without compromising encryption. This enables both data protection through encryption and detectability of malicious activities through behavioral analysis.

Inventive Principle:
Principle #23Feedback

3Loss of information

If all traffic is encrypted for security, then confidentiality is improved, but pattern matching becomes inapplicable

Engineering Contradiction:
ImproveconfidentialityVSAvoidanalysis capability
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent segments the traffic analysis problem into two parts: encrypted traffic that maintains confidentiality and unencrypted contextual traffic that provides analysis capabilities. By separating the inspection function from the encrypted data stream and applying it to contextual packets instead, the system preserves confidentiality while maintaining analysis capability, avoiding the need for complex decryption mechanisms.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS20240187444A1Analyzing encrypted traffic behavior using contextual traffic data
Publication Date: 2024.06.06 CISCO TECHNOLOGY INC
  • US20240187444A1 patent drawing
  • US20240187444A1 patent drawing
  • US20240187444A1 patent drawing

AI summary

In one embodiment, a device in a network detects an encrypted traffic flow associated with a client in the network. The device captures contextual traffic data regarding the encrypted traffic flow from one or more unencrypted packets associated with the client. The device performs a classification of the encrypted traffic flow by using the contextual traffic data as input to a machine learning-based classifier. The device generates an alert based on the classification of the encrypted traffic flow.