近日，郑州大学刘凯凯团队研究了碳点中长寿命三重激子的时变物理不可克隆函数。2025年8月20日出版的《光：科学与应用》杂志发表了这项成果。

物理不可克隆函数（PUFs）是一种很有前途的不可克隆密码生成技术，它广泛依赖于块元素的随机空间分布。

研究组通过引入具有明亮和长寿命三重态激子的碳点（CD）作为块元素来证明时间相关PUFs （TD-PUFs）。随着时间的推移，构建的TD-PUFs演变成多个不可克隆的PUFs，有效地打破了过渡性PUFs的空间限制，增加了其复杂性，使其更难被攻击。这种时间演化引入了额外的安全层，因为TD-PUFs的动态特性使得攻击者预测或复制其状态变得越来越具有挑战性。

研究组开发了像素矩阵函数（PMF）来描述TD-PUFs的演变过程，从而可以详细分析其动态行为和独特的安全特性。此外，研究组还通过一种蚀刻技术展出了一幅TD-PUFs绘画（30 × 40cm²），在这种技术中，随着时间的推移，在CD的不同三重态激子寿命的驱动下，脉冲的初级结构会发生转变。提出的TD-PUFs概念克服了PUF标签的空间限制，增加了PUF标签的复杂度，使得PUF标签更难被破解。

附：英文原文

Title: Time-dependent physical unclonable functions by long-lived triplet excitons in carbon dots

Author: Hu, Yan-Wei, Cao, Qing, Song, Shi-Yu, Sun, Yuan, Liang, Ya-Chuan, Zhao, Wen-Bo, Lv, Chao-Fan, Shan, Chong-Xin, Liu, Kai-Kai

Issue&Volume: 2025-08-20

Abstract: Physical unclonable functions (PUFs), relying extensively on the random spatial distribution of block elements, are promising technology for generating unclonable cryptograph. Herein, we demonstrate time-dependent PUFs (TD-PUFs) by introducing carbon dots (CDs) with bright and long-lived triplet excitons as block elements. The constructed TD-PUFs evolve into multiple unclonable PUFs over time, effectively breaking the spatial limitation of transitional PUFs and increasing the complexity, making them much more difficult to be attacked. This temporal evolution introduces an additional layer of security, as the dynamic nature of TD-PUFs makes it increasingly challenging for adversaries to predict or replicate their states. We have developed pixel matrix function (PMF) to describe the evolution process of the TD-PUFs, enabling a detailed analysis of the dynamic behavior and unique security features. In addition, we exhibit a TD-PUFs painting (30×40cm2) by an etching technology where the primary structures of the panting undergo a transformation over time, driven by the varying triplet exciton lifetimes of the CDs. The proposed concept of TD-PUFs overcome their spatial limitations and increase the complexity, making the PUF labels more difficulty to be cracked.

DOI: 10.1038/s41377-025-01940-9

Source: https://www.nature.com/articles/s41377-025-01940-9