Oblivious RAM (ORAM) protected access pattern is essential for secure NVM. In the ORAM system, data and PosMap metadata are maps in pairs to perform secure access. Therefore, we focus on the problem of crash consistency in the ORAM system. Unfortunately, using traditional software-based support for ORAM system crash consistency is not only expensive, it can also lead to information leaks. At present, there is no relevant research on the specific crash consistency mechanism supporting the ORAM system. To support crash consistency without damaging ORAM system security and compromising the performance, we propose EHAP-ORAM. Firstly, we analyze the access steps of basic ORAM to obtain the basic requirements to support the ORAM system crash consistency. Secondly, improve the ORAM controller. Thirdly, for the improved hardware system, we propose several persistence protocols supporting the ORAM system crash consistency. Finally, we compared our persistent ORAM with the system without crash consistency support, non-recursive and recursive EHAP-ORAM only incurs 3.36% and 3.65% performance overhead. The results show that EHAP-ORAM not only supports effective crash consistency with minimal performance and hardware overhead but also is friendly to NVM lifetime.

中文翻译：

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EHAP-ORAM：用于非易失性存储器的高效硬件辅助持久性 ORAM 系统

Oblivious RAM (ORAM) 保护访问模式对于安全 NVM 至关重要。在 ORAM 系统中，数据和 PosMap 元数据是成对的映射来执行安全访问。因此，我们重点关注 ORAM 系统中崩溃一致性的问题。不幸的是，使用传统的基于软件的 ORAM 系统崩溃一致性支持不仅成本高昂，还会导致信息泄漏。目前还没有相关研究支持ORAM系统的具体崩溃一致性机制。为了在不损害 ORAM 系统安全性和性能的情况下支持崩溃一致性，我们提出了 EHAP-ORAM。首先分析基础ORAM的访问步骤，得到支持ORAM系统崩溃一致性的基本要求。其次，改进ORAM控制器。第三，对于改进的硬件系统，我们提出了几种支持 ORAM 系统崩溃一致性的持久性协议。最后，我们将我们的持久 ORAM 与没有崩溃一致性支持的系统进行了比较，非递归和递归 EHAP-ORAM 仅产生 3.36% 和 3.65% 的性能开销。结果表明，EHAP-ORAM 不仅以最小的性能和硬件开销支持有效的崩溃一致性，而且对 NVM 寿命也很友好。