Research

Our Research

Our research spans the boundaries of electron devices and systems for addressing the challenges in hardware security, extreme reliability, and low power computing. The following are the sponsored projects in our group:

Edge Storage

In light of exponential data growth, the future of solid-state storage hinges on achieving higher bit densities, enhanced performance, superior energy-efficiency, and heightened resilience, all while safeguarding user security and privacy. Meeting these demands necessitates innovation in storage system design. This project aims at bridging the gap between device and system design concepts  to meet the evolving needs of emerging edge computing and storage applications.

Selected Publications:

  • M. A. Kumar, and B. Ray, “Cross-Temperature Reliability of 3D NAND: Cell-to-Cell Variability Analysis and Countermeasure,” in Proc. of the 2024 IEEE International Reliability Physics Symposium (IRPS), Dallas, TX, April 2024. (Video)
  • Md Raquibuzzaman, A. Milenkovic, and B. Ray, “Layer-to-Layer Endurance Variation of 3D NAND”, in Proc. of the 2022 IEEE International Reliability Physics Symposium (IRPS), Dallas, TX, April 2022. (Video)
  • Md Raquibuzzaman, A. Milinkovic, and B. Ray, “Intra-block Wear-leveling to Counter Layer-to-Layer Endurance Variation of 3D NAND Flash Memory,” IEEE Transaction on Electron Devices, vol. 70, no. 1, pp. 70-75, 2023.

Data Sanitization

This project is investigating new cost-effective instant data sanitization techniques for flash memories. 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 removed from flash memories.

Selected Publications:

  • Md Raquibuzzaman, A. Milinkovic, and B. Ray, “Instant Data Sanitization on Multi-Level-Cell NAND Flash Memory,” in Proceedings of the 15th ACM International Conference on Systems and Storage (SYSTOR ’22), Haifa, Israel, June 2022.(Video)
  • M. Hasan and B. Ray, “Data Recovery from “Scrubbed” NAND Flash Storage: Need for Analog Sanitization,” in Proc. of the 29th USENIX Security Symposium, Boston, MA, Aug. 2020. (Video)

Hardware Security

Hardware security has gained a significant importance due to the proliferation of counterfeit electronic components in the globalized semiconductor supply chain. Our research addresses the hardware security issues for semiconductor supply-chain by providing novel methods for generating hardware security functions from commercial stand-alone memory chips without requiring any hardware modification or system-inconvenient operations.

Selected Publications:

  • Sakib, A. Milenkovic, and B. Ray, “Flash-DNA: Identifying NAND Flash Memory Origins Using Intrinsic Array Properties,” IEEE Transactions on Electron Devices, vol. 68, no. 8, pp. 3794-3800, 2021.
  • Poudel, B. Ray, and A. Milinkovic, “Microcontroller Fingerprinting Using Partially Erased NOR Flash Memory Cells,” ACM Transactions on Embedded Computing Systems, vol. 20, no. 3, article no. 26, 2021.
  • Sakib, A. Milenkovic, and B. Ray, “Flash Watermark: An Anti-Counterfeiting Technique for NAND Flash Memories,” IEEE Transaction on Electron Devices, vol. 67, no. 10, pp. 4172–4177, 2020.
  • P. Poudel, B. Ray, and A. Milinkovic, “Flashmark: Watermarking of NOR Flash Memories for Counterfeit Detection,” in Proc. of the 57th IEEE Design and Automation Conference (DAC), San Francisco, CA, USA, 2020.
  • Sakib, P. Kumari, B.M.S.B. Talukder, M.T. Rahman, B. Ray, “Non-Invasive Detection Method for Recycled Flash Memory Using Timing Characteristics,” MDPI Cryptography, vol. 2, no. 3, pp. 17, Aug. 2018.
  • Ray, and A. Milenkovic, “True Random Number Generation Using Read Noise of Flash Memory Cells,” IEEE Transaction on Electron Devices, vol. 65, no. 2, pp. 963-969, 2018.

Radiation Dosimetry

The project develops a handheld, real-time radiation dosimetry solution using commercially available flash memory chips. Since memory chips are widely used in many embedded systems (e.g., smartphones) and wearable devices (e.g., fitness belts), this project could provide a paradigm shift in radiation dosimetry through distributed smart devices, which will be very useful for health monitoring, remote sensing, military applications, nuclear-reactor safety and space applications. Current radiation sensors require monthly to quarterly replacement, regardless of exposure to radiation. With this technology, there is no need to replace, or send anything out for testing. Instant data processing allows for faster assessment of potential damages as well.

Selected Publications:

  • Kumari, U. Surendranathan, M. Wasiolek, K. Hattar, N.P. Bhat and B. Ray, “Analytical Bit-Error Model of NAND Flash Memories for Dosimetry Application,” IEEE Transactions on Nuclear Science, vol. 69, no. 3, pp. 478-484, 2022.
  • Kumari, L. Davies, N. P. Bhat, E. X. Zhang, M. W. McCurdy, D. M. Fleetwood and B. Ray, “State-of-the-Art Flash Chips for Dosimetry Application,” in Proc. of the IEEE Radiation Effects Data Workshop (REDW), Kona, HI, USA, 2018.