## 4 Results
### Algorithms for Managing Cross-Domain Redundancy in RED/BLACK Systems  
There are two algorithms for managing cross-domain redundancy in RED/BLACK communication systems with two distinct strategies that offer different approaches to resource allocation and system resilience. The first algorithm proposes a unified reserve pool that combines resources from both RED and BLACK domains. This integrated approach allows for dynamic allocation of reserve resources across domains as needed. Under this model, when a failure occurs in either domain, the system can draw from the combined pool of reserve radio stations, regardless of their original domain designation. The advantages of this unified approach include the following:  
* Improved resource efficiency, as all reserve units are available to both domains. * Potentially faster response to failures, as there's no need to exhaust one domain's resources before accessing the other. The second algorithm proposes a more conservative, staged approach to cross-domain redundancy. In this model, each domain (RED and BLACK) initially operates with its own dedicated reserve pool. The RED domain, being a higher priority, gains access to BLACK domain resources only after exhausting its own reserves. This approach maintains a stricter separation between domains under normal operating conditions. Advantages of this staged approach include the following:  
* Cleaner security boundaries between domains during normal operations. * Simplified resource management within each domain. Both algorithms offer unique trade-offs between security, efficiency, and complexity. The choice between them would depend on specific operational requirements, security policies, and risk tolerance of the critical infrastructure system. Our analysis focuses on quantifying the reliability improvements offered by each strategy compared to systems without cross-domain redundancy. The following results present the comparative performance of these models under various operational scenarios and system configurations. To analyze algorithms for managing cross-domain redundancy in RED/BLACK communication systems, we will use the Markov chain models. The Markov model, with its memoryless property, is particularly suited for analyzing communication systems because it can model the probabilities of failures and recoveries based on the current state of the system without the need for historical data. For example, if a communication channel within the RED domain is in a 'degraded' state, the Markov model can predict the likelihood of it failing completely or recovering to full functionality in the next time step. This probabilistic analysis provided by the Markov chain allows us to identify weak points in the communication architecture and to design redundancies and safeguards that can improve the overall reliability of the RED domain. By simulating various scenarios through the Markov model, we can anticipate the behavior of the communication channels during different operational conditions and can implement strategic improvements. Furthermore, the Markov model can bridge the gap between theoretical resilience and practical performance. It provides a quantitative framework that can inform the development of protocols and technologies to bolster the security and reliability of the RED domain, ensuring that classified information remains protected while maintaining the continuous flow of communication necessary for effective operations. In this case, the Markov model serves as an important tool in the risk management and optimization of secure communication channels within the RED/BLACK domains. The reliability analysis presented in this study focuses on steady-state reliability, which pertains to the long-term behaviour of the system once it has reached a regime condition. Steady-state analysis is particularly useful for evaluating the long-term availability and reliability of systems, which is critical for dual-priority communication systems where continuous and reliable operation is paramount.