Security aware dynamic scheduling algorithm (SADSA) for real-time applications on grid

Security is a major concern of modern real-time applications, besides requiring stringent latency bound. However, encryption algorithms are computation intensive task which impacts the timeliness of the real-time applications. Therefore, there exists a trade-off between the desired level of security and the service guarantee. In this paper, we propose a security-aware dynamic scheduling algorithm (SADSA) using a grid of computational elements (CEs) which performs this trade-off and tries to maximize the instantaneous average security level of the packets besides providing a guaranteed service. As packets arrive, we first assign them to the CEs based on the utilization value of a CE, which is the ratio of completion time and a deadline of the last packet in a CE. The security level of all the packets is then dynamically adjusted to meet the minimum required security level while maximizing the average security level of all the packets in that CE. We first show that the proposed assignment algorithm is NP-hard, is 2-competitive to the optimal solution, and that the proposed algorithm provides a sub-optimal solution. Further, using extensive simulation, we show that the proposed SADSA algorithm performs better in terms of guarantee ratio, average security level and overall performance compared to the existing algorithms.