[论文解读] Highly-Secure Physically Unclonable Cryptographic Primitives Using Nonlinear Conductance and Analog State Tuning in Memristive Crossbar Arrays

Hussein Nili, Gina C. Adam+5 more|arXiv (Cornell University)|Nov 23, 2016

Advanced Memory and Neural Computing参考文献 37被引用 3

一句话总结

本文提出一种高度安全、可重构的物理不可克隆功能（PUF）原语，采用具有非线性I-V特性和模拟电导调节功能的3D忆阻交叉阵列。通过利用250-nm半节距忆阻器的工艺诱导变异，原型实现了接近理想的均匀性（50% ± 5%）和扩散性，在电源电压波动下30天内误码率仅为约1.5%，可生成超过10^19个唯一的挑战-响应对。

ABSTRACT

The rapidly expanding hardware-intrinsic security primitives are aimed at addressing significant security challenges of a massively interconnected world in the age of information technology. The main idea of such primitives is to employ instance-specific process-induced variations in electronic hardware as a source of cryptographic data. Among the emergent technologies, memristive devices provide unique opportunities for security applications due to the underlying stochasticity in their operation. Herein, we report a prototype of a robust, dense, and reconfigurable physical unclonable function primitives based on the three-dimensional passive metal-oxide memristive crossbar circuits, by making positive use of process-induced variations in the devices' nonlinear I-Vs and their analog tuning. We first characterize security metrics for a basic building block of the security primitives based on a two layer stack with monolithically integrated 10x10 250-nm half-pitch memristive crossbar circuits. The experimental results show that the average uniformity and diffusivity, measured on a random sample of 6,000 64-bit responses, out of ~697,000 total, is close to ideal 50% with 5% standard deviation for both metrics. The uniqueness, which was evaluated on a smaller sample by readjusting conductances of crosspoint devices within the same crossbar, is also close to the ideal 50% +/- 1%, while the smallest bit error rate, i.e. reciprocal of reliability, measured over 30-day window under +/-20% power supply variations, was ~ 1.5% +/- 1%. We then utilize multiple instances of the basic block to demonstrate physically unclonable functional primitive with 10-bit hidden challenge generation that encodes more than 10^19 challenge response pairs and has comparable uniformity, diffusiveness, and bit error rate.

研究动机与目标

• 开发一种利用硬件内在变异实现强安全性的物理不可克隆功能（PUF）原语，以增强互联系统的安全性。
• 利用忆阻器件的随机行为生成唯一且不可预测的密码学响应。
• 在密集且可重构的架构中展示高均匀性、高扩散性和高可靠性，适用于硬件安全应用。
• 将基本PUF模块扩展为更大功能的原语，具备隐藏挑战生成机制与海量CRP空间。

提出的方法

• 设计并制造具有10×10 250-nm半节距布局的3D无源金属氧化物忆阻交叉阵列。
• 利用交叉点忆阻器非线性I-V特性中的工艺诱导变异作为随机性来源。
• 实现模拟电导调节以重构PUF状态，提升可重用性。
• 采用多层堆叠的2层交叉阵列模块，构建10位隐藏挑战生成器，实现高熵。
• 在环境变化条件下表征安全性指标，包括均匀性、扩散性和误码率。
• 通过在相同交叉阵列内重新调节电导并测量响应差异，评估唯一性。

实验结果

研究问题

• RQ1 具有非线性I-V特性的忆阻交叉阵列能否生成接近理想均匀性和扩散性的PUF响应？
• RQ2 模拟电导调节在多大程度上可实现可重构性，同时保持PUF的安全特性？
• RQ3 该系统在长时间运行期间，面对电源电压波动，如何维持低误码率？
• RQ4 基于堆叠忆阻交叉阵列的可扩展PUF架构中，可实现的熵值与挑战-响应对空间有多大？

主要发现

• 6,000个采样64位响应的平均均匀性与扩散性为50% ± 5%，接近理想理论极限。
• 通过在相同交叉阵列内重新调节电导测量的PUF唯一性为50% ± 1%，表明响应具有高度多样性。
• 在±20%电源电压波动下，30天内测得误码率为~1.5% ± 1%，证明系统具有高可靠性。
• 成功演示了一种具备10位隐藏挑战生成能力的可扩展PUF原语，编码超过10^19个唯一挑战-响应对。
• 系统在多个测试样本中保持一致的安全指标，证实其鲁棒性与可重复性。