The evolution of quantum computers poses a serious threat to contemporary public-key encryption (PKE) schemes. To address this impending issue, the National Institute of Standards and Technology (NIST) is currently undertaking the Post-Quantum Cryptography (PQC) standardization project intending to evaluate and subsequently standardize the suitable PQC scheme(s). One such attractive approach, called Bit Flipping Key Encapsulation (BIKE), has made to the final round of the competition. Despite having some attractive features, the IND-CCA security of the BIKE depends on the average decoder failure rate (DFR), a higher value of which can facilitate a particular type of side-channel attack. Although the BIKE adopts a Black-Grey-Flip (BGF) decoder that offers a negligible DFR, the effect of weak-keys on the average DFR has not been fully investigated. Therefore, in this paper, we first perform an implementation of the BIKE scheme, and then through extensive experiments show that the weak-keys can be a potential threat to IND-CCA security of the BIKE scheme and thus need attention from the research community prior to standardization. We also propose a key-check algorithm that can potentially supplement the BIKE mechanism and prevent users from generating and adopting weak keys to address this issue.
翻译:量子计算机的演变对当代公用钥匙加密(PKE)计划构成严重威胁。为解决这一迫在眉睫的问题,国家标准和技术研究所(NIST)目前正在实施“量子加密后”标准化项目(PQC),旨在评估和随后使适当的PQC计划标准化。这种称为Bit Flipping Key Capulation(BIKE)的吸引人的方法之一,对最后一轮竞争进行了充分调查。尽管具有一些吸引人的特点,但BIKE的IND-CCA安全性取决于平均解码失败率(DFR),而后者的较高价值可以促进某种特定的侧道攻击。虽然BIKE采用了一个提供微不足道DFR(BGF)的黑-GFLip(BGF)解码器,但弱钥匙对平均DFR(BKE)的影响还没有得到充分调查。因此,我们首先执行BIKE计划,然后通过广泛的实验表明,弱钥匙可能对IND-CCA系统造成潜在的威胁,因此BK计划所需的关键研究机制需要我们先提出“CE”的标准化。