IPsec Gateway Segmentation for Red-Black Network Security

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Solution Overview

Problem

Entities with high security requirements for Red-Black network separation and fault tolerance have to use expensive, custom-built systems, as off-the-shelf IPSec implementations fail to meet these needs effectively.

Innovation Solution

A cryptographic system and method that uses commercial IPSec implementations, where an IP stack prepares messages for encryption and decryption, with cryptographic operations performed by separate modules in protected memory, minimizing the risk of sensitive data compromise by isolating keys from the IP stack and using a security monitor for redundant encryption and CRC verification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If commercial IPSec implementations are used, then cost is reduced, but security requirements cannot be met

Engineering Contradiction:
ImprovecostVSAvoidsecurity requirements
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The system divides the IPsec gateway functionality into separate modules: a commercial IP stack for network protocols and a separate cryptographic module for security operations. This segmentation allows the use of cost-effective commercial software while maintaining high security through isolated cryptographic operations that cannot be compromised by the IP stack.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A protected memory space acts as an intermediary between the commercial IP stack and the cryptographic operations. Keys and sensitive cryptographic data are stored in this protected memory, which isolates them from the IP stack while allowing the IP stack to access them through controlled interfaces, thus maintaining both cost-effectiveness and security.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If custom-built systems are used to meet high security requirements, then security and fault tolerance are improved, but cost increases

Engineering Contradiction:
Improvesecurity and fault toleranceVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By segmenting the system into a commercial IP stack and a separate cryptographic module with protected memory, the patent achieves high security and fault tolerance without requiring expensive custom-built systems. The segmentation ensures that cryptographic operations are isolated from potential vulnerabilities in the commercial software.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a virtual machine monitor that creates a virtualized cryptographic environment, effectively copying secure cryptographic functionality into a protected virtual space. This allows high-assurance security to be achieved by running cryptographic operations in an isolated virtual environment rather than building custom hardware systems.

Inventive Principle:
Principle #26Copying

3Ease of operation

If keys are accessible to the IP stack, then ease of operation is improved, but security risk increases

Engineering Contradiction:
Improvekey accessibilityVSAvoidsecurity risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Protected memory serves as an intermediary between the IP stack and cryptographic keys. The IP stack can request cryptographic operations through controlled interfaces, but keys remain isolated in protected memory, preventing direct access while maintaining operational capability through the intermediary layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system segments the memory space into unprotected memory for the IP stack and protected memory for cryptographic operations. This segmentation maintains ease of operation by allowing the IP stack to initiate cryptographic operations while preventing direct access to keys, thus reducing security risks.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2359522B1Method and system to construct a high-assurance IPsec gateway using an unmodified commercial implementation
Publication Date: 2014.04.02 MOTOROLA SOLUTIONS INC
  • EP2359522B1 patent drawingFigure 1
  • EP2359522B1 patent drawingFigure 2
  • EP2359522B1 patent drawingFigure 3

AI summary

A system and method of providing secure communications is provided. Messages are encrypted or decrypted in protected memory of a processor. Outbound messages from a secure network are prepared for encryption by adding a header outside of the protected memory and then encrypted in the protected memory. The encryption is performed by retrieving a key from a key cache as designated by rules in the header. The encrypted message is sent to the unsecure network. An inbound message from an unsecure network that is received in unprotected memory is sent to a decryption module in protected memory. The inbound message is decrypted using a key designated in its header and retrieved from the key cache. The decrypted message is returned to the unprotected memory, where it is stripped of the encryption header and then sent to its destination within the secure network.