【摘要】 首先在分析嵌入式实时数据库安全要求的基础上,给出了一个三层安全控制模型。然后提出一种安全乐观并发控制策略。该策略采取向前验证策略检查是否发生冲突,当事务执行到验证阶段,当可能出现违背安全要求时,则分别计算提交或夭折被验证事务所引起违背安全及实时要求的严重程度,以决定是否提交或夭折被验证事务。该策略具有较大的灵活性,用户可根据系统的安全要求和实时特征动态调整产生隐通道严重程度及超截止期严重程度的权值以适应不同要求。更多还原

【Abstract】 This passage bulids a secure control model with three layers on the ERTDB security requirements firstly,and then proposes a secure optimistic concurrency control strategy.It takes FV(Forward Validation) strategy to test the conflict.In the validation phase, when there will be a security conflict,we calculate the violation severity of security and timeless respectively which proceeded from aborting or committing the validating transaction ,and then makes decision according to the result.This strategy is comparatively flexible,users can adjust the weight of covert channel and missing deadline severity dynamically so as to meet different timeless and security requirement of the system.更多还原