Memory: 3D NAND PUF; ternary alloy for NVM; quantum RAM with phonons.
Researchers from Seoul National University developed a new hardware security technology based on commercially available 3D NAND flash memory. The approach is an adaptation of physical unclonable functions (PUFs) with the ability to hide a security key under user data when not in use and reveal it only when needed. The same memory space used for storing security keys can be repurposed for general data storage.
To achieve this, the team employed a weak application of the gate-induced drain leakage (GIDL) erase mechanism in V-NAND flash memory to deliberately amplify the variation in erase levels between memory cells, thereby enabling the generation of PUF data.
In tests using commercial V-NAND flash memory, the generated PUF data maintained 100% accuracy and randomness across various conditions, including temperature variations from 25°C to 85°C and over 10 million read cycles. The key conceal-and-reveal function was successfully repeated over 100 times without error, and simulated machine learning attacks were only able to predict the keys at a level consistent with random guessing.
“This research is significant because it demonstrates how PUFs can be implemented using the erase operation of existing V-NAND flash memory without altering the circuitry or design,” said Sung-Ho Park, a doctoral student at Seoul National University, in a release. “By enabling selective exposure of the security key, our method opens up new possibilities for enhancing both security and memory efficiency.” [1]
Researchers from the Institute of Science Tokyo, Tokyo Institute of Technology, and Tosoh Corporation incorporated scandium (Sc) into gallium nitride (GaN) and aluminum nitride (AlN) thin films, creating a ternary alloy with properties that could be used as the foundation for non-volatile memory with reduced operating voltages and improved noise filters.
The team created a range of ternary alloys with different proportions of each element. Reactive magnetron sputtering to deposit thin films of the three materials onto platinum- and titanium-coated silicon substrates, which were then characterized using techniques including X-ray diffraction and electron microscopy to map out a phase diagram.
They found that as Sc content was increased, there was a significant reduction in the material’s coercive field (Ec) needed to switch polarization, decreasing from 5.8 MV/cm to 1.8 MV/cm as the Sc ratio grew larger.
“This Ec value is much lower than most reported values in previous works for various dopants of AlN- and GaN-based wurtzite films, which is very promising for the development of memory devices,” said Hiroshi Funakubo, a professor at Science Tokyo, in a statement. “These properties open up potential applications in high-frequency noise filters and ultra-low-power optical computing systems, which are necessary for next-generation 6G smartphones and in optical computing devices that operate with ultra-low power.” [2]
Researchers from the University of Chicago propose a quantum RAM architecture that uses a branching, tree-like pattern of routers made from transmons, a type of quantumly entangled bit, to direct individual phonons, the vibrations that make up sound.
“In classical RAM, you’re taking an address as the input, and then it returns the data at that location,” said Zhaoyou Wang, a UChicago PME postdoctoral researcher, in a press release. “But QRAM, you are taking a superposition of addresses, so you query different memory locations in terms of quantum superposition, and that will return all the results in parallel.”
“The hybrid combination of phonons and superconducting qubits to make functional quantum elements is a brand-new area that very few other groups are developing,” explained Andrew Cleland, a professor at UChicago PME, in a press release. “This is mostly because the community has not yet understood that some capabilities are actually easier to implement with phonons than with other technologies, and we are really taking advantage of this relative simplification to do new things.”
Using phonons means the final device more compact, scalable, and practical for real-world applications, according to the researchers. The structure also avoids frequency crowding. While the QRAM supports error detection, the team’s next steps are to implement error correction and build the actual device. [3]
[1] SH. Park, RH. Koo, Y. Yang, et al. Concealable physical unclonable functions using vertical NAND flash memory. Nat Commun 16, 5155 (2025). https://doi.org/10.1038/s41467-025-60415-y
[2] R. Ota, N. Sun, K. Okamoto, et al. Impact of film composition on crystal structure and ferroelectricity in (Al1−x−yGaxScy)N ternary wurtzite thin films. APL Mater. 1 April 2025; 13 (4): 041120. https://doi.org/10.1063/5.0261572
[3] Z. Wang, H. Qiao, A. Cleland, L. Jiang. Quantum Random Access Memory with Transmon-Controlled Phonon Routing. Physical Review Letters, May 28, 2025. https://dx.doi.org/10.1103/PhysRevLett.134.210601
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