SDN Controller Trust via Multi-Controller Consistency Assessment

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Solution Overview

Problem

Current SDN technologies lack effective detection mechanisms for tampered controllers or applications that could send malicious configurations to network switches, leading to potential attacks and compromised network security.

Innovation Solution

Implementing a method that involves selecting multiple SDN controllers with diverse execution environments, duplicating network modification requests, and assessing consistency among their responses to determine the trustworthiness of configuration requests, using trust-oriented controller proxies and policies to enforce trustworthy configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a single centralized SDN controller is used to provide network programmability and dynamic control, then network flexibility and automation are improved, but security vulnerability and risk of total network control by attacker increase

Engineering Contradiction:
Improvenetwork automationVSAvoidcontroller security
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent divides the single centralized controller into multiple redundant controllers. Each controller can independently process network modification requests, and the system selects trustworthy controllers based on consistency assessment. This segmentation prevents a single point of failure and limits the impact of compromised controllers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates multiple copies of the controller system with diverse execution environments. Each controller generates a response to the same network modification request, and these responses are compared for consistency. The copying approach enables redundancy and trust assessment without requiring a single authoritative controller.

Inventive Principle:
Principle #26Copying

2Reliability

If multiple redundant SDN controllers are deployed to improve fault tolerance and response time, then system reliability and performance are improved, but detection of tampered controllers becomes more difficult

Engineering Contradiction:
Improvecontroller availabilityVSAvoidtampered controller detection
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a feedback mechanism where controllers provide responses to network modification requests, and these responses are assessed for consistency. The system uses this feedback to identify tampered controllers by detecting inconsistencies in the responses from multiple controllers.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a trust assessment mechanism as an intermediary between controllers and network devices. This intermediary evaluates the consistency of controller responses and determines which controllers are trustworthy, preventing tampered controllers from directly affecting network operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If known security approaches such as priority-based request processing are implemented, then protection against tampered applications is improved, but detection of successful attacks remains insufficient

Engineering Contradiction:
Improveapplication protectionVSAvoidattack detection
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent sends the same network modification request to multiple controllers and compares their responses. This copying approach enables detection of tampered controllers because inconsistent responses reveal malicious behavior, whereas single-request approaches cannot detect successful attacks.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent uses feedback from multiple controller responses to assess trustworthiness. By analyzing the consistency of feedback from multiple controllers, the system can detect attacks that single-request processing would miss, as tampered controllers would produce inconsistent responses.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3079302B1Method and system for improving the network configuration trustworthiness in a software defined network
Publication Date: 2019.06.19 ALCATEL LUCENT SA
  • EP3079302B1 patent drawingFigure 1
  • EP3079302B1 patent drawingFigure 2

AI summary

A method for improving the network configuration trustworthiness in a software defined network (SDN), this network comprising a plurality of SDN controllers that can receive network modification requests generated by SDN applications, and at least one SDN device that can receive network modification requests generated by the SDN controllers, comprises the steps of: - receiving (1) a first network modification request generated by a SDN application; - selecting (2) a plurality of controllers; - supplying (3) the first network modification request to the selected controllers; - generating (4) a second network modification request in each selected controller when it receives the first network modification request; - collecting (5) second network modification requests respectively generated by the selected controllers when they receive the first network modification request, and assessing (5) the consistency of these second network modification requests; - and enforcing (6, 7) a third network modification request in at least one SDN device if, and only if, the value of the assessed consistency is greater than a predetermined threshold.