Abstract: Given the security challenges faced for the dependent task-scheduling problem under heterogeneous grid environment,considering grid nodes’ inherent security and behavioral security,we built a function to measure each node’s identical reliability and a strategy to assess its behavioral credibility.Meanwhile,in order to establish the affiliation between the security requirement and security attributes of each task,an affiliation function of security benefits was defined.Thus,a security trusted task-scheduling model under grid environment was built in this paper.On this basis,with the task’s requirement model presented and grid resources’ topology model introduced,a new security trusted grid task-scheduling model was proposed.To solve this model by using genetic algorithm,we designed several new genetic operators,including improved crossover operator,crossover operator within each individual and migration operator which is taken as mutation operator,and at the same time,with a view to increase search precision,the simulated annealing algorithm was introduced,by which we further proposed a new genetic-annealing algorithm.The simulation results show that compared with similar algorithms under the same conditions,the proposed algorithm has a better overall performance in terms of scheduling length,security trusted value,convergence and other aspects.

Key words: Grid computing,Task-scheduling,Security trusted model,Evolution operator,Genetic-annealing algorithm