Research On Metadata Crash Consistency Guarantee Mechanism In Secure Non-Volatile Memory

The non-volatility of non-volatile memory(NVM)enables the persistent storage of data in memory.However,it also brings new challenges to the design of memory security mechanisms.Persistent storage of data requires the NVM system to achieve the crash consistency of security metadata,ensuring the matching between user data and security metadata.Existing works on the crash consistency guarantee of security metadata either incur extra NVM writes or damage the system reliability,which is unfriendly to NVM with expensive writes and high error rates.In order to reduce the NVM write traffic introduced by the crash consistency guarantee mechanism without impairing the system reliability,a crash consistency guarantee method based on metadata recoverability(CCMR)is proposed.CCMR relaxes the requirement of the security metadata persistency and avoids writing every update of the metadata back to NVM.During the crash recovery period,CCMR will bring the security metadata back to the latest state by leveraging the internal relationship among them,so as to realize the crash consistency guarantee of the security metadata.To reduce the access overhead of the counter and the data message authentication code(DMAC),counter-DMAC coordinated storage(Ctr D)is come up with to improve the access efficiency of the security metadata.Aiming at the problem of a large bandwidth waste in the traditional address tracker for fast recovery,a lightweight address tracker(light?AT)is designed to delay and absorb address writes.Based on the optimization schemes mentioned above,the prototype system Necco is implemented.Necco is tested by the widely used persistent benchmark.Experiments show that compared to the state-of-the-art scheme PSIT?DMAC,Necco improves the performance by 20.3%,decreases the NVM write traffic by 48.5% on average,and only takes 0.02 s to achieve the correct recovery of the security metadata.Besides,compared to the Baseline without the crash consistency guarantee,Necco only incurs 3.9% extra NVM write traffic.