Back-end Constrained Delegation Model for Multi-Domain Security
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Constrained delegation in networked computing systems is difficult to implement across multiple domains due to the need for cooperation among multiple domain controllers, focusing on domain policies rather than individual back-end tier server policies, which limits flexibility and security.
Innovation Solution
The delegation model determines whether a middle tier computing device can delegate to back-end tier devices based on the individual policies of those devices, allowing domain administrators to validate and provide service tickets or tokens for secure communication, reducing the role of domain administrators and enhancing policy enforcement by back-end tier server administrators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If constrained delegation is implemented across multiple domains using traditional domain controller policies, then security is improved through centralized control, but device complexity and administrative coordination requirements increase significantly
Solution Approach 1:
The patent segments the centralized delegation control into distributed server-specific policies. Each back-end tier server maintains its own delegation policy independently, eliminating the need for coordinated domain controller policies across multiple domains. This segmentation allows security to be enforced at each server level without requiring complex inter-domain controller coordination.
Solution Approach 2:
The service ticket acts as an intermediary mechanism that enables delegation verification without requiring direct trust relationships between domain controllers. The middle tier computing device obtains a service ticket from the back-end tier server's domain controller, which serves as proof of authorized delegation, eliminating the need for direct domain controller cooperation.
2Ease of operation
If domain administrators maintain centralized control over delegation policies, then security management is simplified, but back-end tier servers lose flexibility in controlling their own access policies
Solution Approach 1:
The patent enables back-end tier servers to manage their own delegation policies autonomously. Each server can independently define which middle tier computing devices are authorized to delegate to it, and the server itself verifies these policies using service tickets. This self-service approach gives servers flexibility while maintaining security without requiring domain administrator intervention for each policy decision.
3Ease of operation
If unconstrained delegation is allowed for simplicity, then ease of operation is improved, but security is compromised as middle tier servers can communicate with any server
Solution Approach 1:
The patent applies different delegation control mechanisms to different back-end tier servers based on their specific security requirements. Each server can have customized delegation policies tailored to its local security needs, rather than applying a uniform domain-wide policy. This allows simple delegation setup where needed while maintaining strict security controls where required.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A client can communicate with a middle tier, which can then, in turn, communicate with a back end tier to access information and resources on behalf of the client within the context of a system that can scale well. Each individual back end can establish a policy that defines which computing device can delegate to that back end. That policy can be enforced by a domain controller within the same administrative domain as the particular back end. When a middle tier requests to delegate to a back end, the domain controller to which that request was directed can either apply the policy, or, if the domain controller is in a different domain than the targeted back end, it can direct the middle tier to a domain controller in a different domain and can sign relevant information that the middle tier can utilize when communicating with that different domain controller.