面向车载自组网的无证书聚合签名方案的安全性分析与改进

2018年，王大星和滕济凯提出了一种适用于车载自组织网络的无证书聚合签名方案，并在随机模型下证明该方案是存在不可伪造的。针对该方案的安全性，给出了3类伪造攻击:“honest-but-curious”的KGC攻击、恶意的KGC与RSU的联合攻击、内部签名者的联合攻击。分析结果表明，王大星等人设计的无证书聚合签名方案在这3类攻击下均是不安全的。为了抵抗这些攻击，进一步提出了一个改进的无证书聚合签名方案。所提方案不仅在自适应性选择消息攻击下满足存在不可伪造性，还能有效抵抗联合攻击。

Security Analysis and Improvement of Certificateless Aggregate Signature Scheme for Vehicular Ad Hoc Networks

In 2018, Wang Daxing and Teng Jikai proposed a certificateless aggregate signature scheme for vehicular ad-hoc networks, and proved that their scheme was existentially unforgeable in the random oracle model. To analyze the security of this scheme, three types of forgery attacks are given: " honest-but-curious” KGC attacks, malicious KGC and RSU coalition attacks, and internal signers’ coalition attacks. The analysis results show that the certificateless aggregate signature scheme designed by Wang Daxing and Teng Jikai is insecure against these three types of attacks. To resist these attacks, an improved certificateless aggregate signature scheme is further proposed. The new scheme not only satisfies existential unforgeability under adaptive chosen-message attacks, but also resists effectively coalition attacks.