CNS Core: Small: Ensuring Privacy by Runtime Analog Sanitization of Solid State Storage Devices

非易失性闪存是固态存储设备的基本构建块，在消费电子、汽车、军事、工业、医疗保健和企业领域的各种计算系统中提供小巧、高容量、高速和低功耗的永久存储解决方案。遗憾的是，即时从物理闪存中删除数据并不总是一帆风顺的，因为它会带来巨大的开销并增加磨损程度，尤其是在固态硬盘(SSD)中。根据最近的一份报告，eBay上出售的旧SSD中有42%持有敏感的可恢复数据，尽管数据删除或清理方法已经到位。虽然标准的数据删除方法使用户无法通过标准接口访问数据，但我们最近的研究成果表明，通过闪存单元的物理特征，删除的数据可以部分或完全恢复。这突显了需要找到新的方法来确保从闪存中迅速、永久且不可逆转地重新移动已删除的数据。该项目正在研究新的高性价比的闪存即时数据清理技术。所提出的技术利用了(A)最近闪存操作的时间线；(B)由状态衰减模型覆盖的闪存单元的物理属性；以及(C)部分闪存编程和擦除操作。这些技术将被量身定做，以使商业存储应用中的闪存芯片的独特属性和架构变得通用。所提出的技术将适用于不同类型的闪存，将不需要或最小程度地改变硬件，并且不会增加闪存的磨损水平，也不会显著增加普通闪存操作的等待时间。在运行时对闪存进行经济高效的数据清理技术可确保删除的数据在产品生命周期内的任何时候都不可恢复，从而使消费者、行业和政府都受益。这些技术将部署在闪存控制器的固件中。这一提议的直接结果将是在面向硬件的安全和存储系统这一重要领域培训三名研究生。调查人员正在开发教材，在嵌入式系统、计算机系统架构和硬件可靠性课程中介绍面向硬件的安全主题。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-volatile flash memories, the basic building blocks of solid-state storage devices, offer small form factors, high-capacity, high-speed, and low-power permanent storage solutions in a wide range of computing systems found in consumer electronics, automotive, military, industrial, healthcare, and enterprise segments. Unfortunately, deleting data instantly from physical flash memories is not always straightforward as it incurs hefty overheads and increases wear level, especially in solid-state drives (SSDs). According to a recent report, 42% of used SSDs sold on eBay held sensitive recoverable data, even though data deletion or sanitization methods were in place. Whereas standard data deletion methods make the data inaccessible to the user through standard interfaces, our recent research efforts demonstrate that the deleted data is partially or fully recoverable by means of physical characterization of flash memory cells. This underscores the need for finding new ways to ensure that deleted data is promptly, permanently, and irreversibly re-moved from flash memories. This project is investigating new cost-effective instant data sanitization techniques for flash memories. The proposed techniques take advantage of (a) timeline of recent flash operations; (b) physical properties of flash memory cells cap-tured by state decay models and (c) partial flash program and erase operations. These techniques will be tailored to uti-lize the unique properties and architectures of flash-memory chips found in commercial storage applications. The proposed techniques will be applicable to different types of flash memories, will require no or minimal changes in hardware, and will not increase the wear level of flash memories nor significantly increase the latency of common flash operations. Techniques for cost-effective data sanitization of flash memories in run-time will benefit consumers, industry, and government alike by ensuring that deleted data is not recoverable at any time during the product’s life cycle. These techniques will be deployed in the firmware of flash memory controllers. A direct outcome of this proposal will be the training of three graduate students in the important area of hardware-oriented security and memory systems. The investigators are developing teaching materials to introduce hardware-oriented security topics in embedded systems, computer systems architecture, and hardware reliability courses.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.