摘要： 目前基于身份的广播加密方案多为非匿名方案，安全性较差。为此，将基于身份的匿名加密定义拓展为基于身份的匿名广播加密，在Zhang等人方案(Mathematical and Computer Modelling, 2012, No.1)的基础上，结合合数阶双线性群的性质，并基于3个静态假设，构造一种基于身份的匿名广播加密方案。该方案的安全性不依赖于随机预言机，其中的密文和私钥均为固定长度，安全性可达到适应性安全。同时方案具有匿名性，敌手不能通过密文得到接收者的任何身份信息，从而保护了接收者的隐私。通过分析方案的效率验证了其正确性和安全性，并与同类方案进行比较，表明该方案更具优势。
关键词:
广播加密,
匿名,
合数阶双线性群,
基于身份的匿名加密,
基于身份的匿名广播加密,
静态假设
Abstract: Most of the current broadcast encryption schemes are not anonymous. Aiming at this problem, a new anonymous Identity-based Broadcast Encryption(IBBE) scheme is constructed. It extends the definition of anonymous Identity-based Encryption(IBE) to anonymous IBBE. Combining with Zhang’s scheme(Mathematical and Computer Modelling, 2012, No.1), the new anonymous IBBE scheme is based on three static assumptions and a bilinear group of composition order. Results show that the scheme’s security does not rely on the random oracles. There is a constant ciphertexts and private key length in the scheme. Most importantly, it achieves an adaptive security and anonymous property. The adversary cannot get recipient’s any identity information, so receiver’s privacy can be protected well. Finally, the efficiency of the scheme is analyzed and the correctness and security are verified. Then, the performance of this scheme is compared with similar schemes, and result shows that the proposed scheme has better performance.
Key words:
broadcast encryption,
anonymous,
bilinear group of compositing order,
anonymous Identity-based Encryption(IBE),
anonymous Identity-based Broadcast Encryption(IBBE),
static assumption
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