Post-quantum multivariate public key cryptography (MPKC) schemes resist quantum threats but require heavy operations, such as rejection sampling, which challenge resource-limited devices. Prior hardware designs have addressed various aspects of MPKC signature generation. However, rejection sampling remains largely unexplored in such contexts. This paper presents RejSCore, a lightweight hardware accelerator for rejection sampling in post-quantum cryptography. It specifically targets the QR-UOV scheme, which is a prominent candidate under the second-round of the National Institute of Standards and Technology (NIST) additional digital signature standardization process. The architecture includes an AES-CTR-128-based pseudorandom number generator. Moreover, a lightweight iterative method is employed in rejection sampling, offering reduced resource consumption and area overhead while slightly increasing latency. The performance of RejSCore is comprehensively evaluated on Artix-7 FPGAs and 65 nm CMOS technology using the Area-Delay Product (ADP) and Power-Delay Product (PDP). On Artix-7 and 65 nm CMOS, RejSCore achieves an area of 2042 slices and 464,866~$\mu m^2$, with operating frequencies of 222 MHz and 565 MHz, respectively. Using the QR-UOV parameters for security level I ($q = 127$, $v = 156$, $m = 54$, $l = 3$), the core completes its operation in 8525 clock cycles. The ADP and PDP evaluations confirm RejSCore's suitability for deployment in resource-constrained and security-critical environments.

翻译：后量子多元公钥密码学（MPKC）方案能够抵御量子威胁，但需要执行诸如拒绝采样等繁重运算，这对资源受限设备构成了挑战。先前的硬件设计已针对MPKC签名生成的多个方面进行了优化，然而，拒绝采样在此类场景中仍未得到充分探索。本文提出RejSCore，一种用于后量子密码学中拒绝采样的轻量级硬件加速器。它专门针对QR-UOV方案——该方案是美国国家标准与技术研究院（NIST）第二轮附加数字签名标准化进程中的重要候选方案。该架构包含一个基于AES-CTR-128的伪随机数生成器。此外，拒绝采样采用了一种轻量级迭代方法，在略微增加延迟的同时，降低了资源消耗和面积开销。RejSCore的性能在Artix-7 FPGA和65 nm CMOS工艺上通过面积-延时积（ADP）和功耗-延时积（PDP）进行了全面评估。在Artix-7和65 nm CMOS上，RejSCore分别实现了2042个逻辑片和464,866~$\mu m^2$的面积，工作频率分别为222 MHz和565 MHz。采用安全等级I的QR-UOV参数（$q = 127$，$v = 156$，$m = 54$，$l = 3$）时，该核心在8525个时钟周期内完成运算。ADP和PDP评估结果证实了RejSCore适用于资源受限且对安全性要求严苛的部署环境。