Exploring The Durability And Security Issues Of NVM-based Main Memory In Mobile Devices

With the rapid development of information technology, the mobile devices have been applied to big data, cloud computing, internet of things and other fields. Meanwhile, the performance of storage, capacity, energy consumption,reliability and costs are needed to be improved as well. The energy consumption and limited scalability of DRAM become the bottleneck of the development of mobile device. It is urgently to find a replacement technology. Emerging non-volatile memory has many attractive advantages, such as non-volatile, low energy consumption, byte-addressable, low latency, high density and high scalability. It has emerged as promising alternative to DRAM for solving the energy and scalability problems. Nevertheless, new non-volatile memory has some constraints, including low endurance and security.To address these above issues, considering the application-specific features of mobile devices, this thesis firstly studies the lifetime of emerging non-volatile memory. Then, we study the write reduction technology in non-volatile memory. After that, by combining with the emerging non-volatile memory, we study the memory security problem in mobile devices. We proposed the encryption mechanism based on indirect encryption technique. The main contributions are listed as follow.First, the mobile devices usually requires frequent update operations to the main memory. A large number of write operations will speed up the wear of nonvolatile memory. Considering the application-specific features and energy consumption limits of mobile devices, we design a write reduction technology by adopting the method of flip and shift to transform the data to be written. The proposed technique is designed for reducing the different bits of the written data and the existing data. Thus, extending life of nonvolatile memory.Second, the nonvolatile nature of nonvolatile memory keeps the data still exist even when the system is powered off. It leads to the security concerns of the privacy data stored in main memory. This paper studies the security of the nonvolatile memory. And we design the encryption scheme based on counter-mode encryption mechanism.Final, in the view of lifetime and security problem of NVM, this paper designs the corresponding simulation to evaluate the performance of the proposed technique. Experimental results show that the proposed technique can reduce the number of writes by 57.3% on average. The lifetime of NVM is 2.3 times longer than before. Comparing with the direct-AES and OTP encryption mechanism, the encryption technique can effectively enhance the security of the main memory with low encryption energy consumption, time delay and storage cost, etc. This paper presents a new idea and direction for the development of NVM in the area of mobile devices, embedded devices, personal PC and data center.