基于双线性映射的多对一加密认证方案

Many-to-One Encryption and Authentication Scheme Based on Bilinear Pairing

研究群组密码学中的一个子类:多对一加密认证方案.该方案主要用于解决分布式系统中的一个实际问题:当有大量用户发送密文给接收者时,如何减轻接收者和KGC的密钥管理负担.使用椭圆曲线上的双线性映射作为工具,在多对一加密认证方案的定义和安全模型下,构造了一个具体的方案,同时证明了该方案的安全性.合法发送者使用他的加密密钥产生密文,该密钥与接收者的身份和解密密钥有关,解密者仅使用他唯一的解密密钥就可以解密任何合法的密文,并可以认证发送者的身份.该方案的计算复杂性和密文长度不依赖于合法发送者的数量.

Many-to-one encryption and authentication scheme, which is a sublcass of group cryptography, is discussed in this paper. This scheme is to resolve a practical problem, when there are many users sending ciphertexts to a receiver, the burdens of the receiver and KGC must be reduced. The number of receivers is very small compared with the number of senders, i. e. , a receiver may serw＂ millions of senders. Compared with the traditional methods, the burdens of the receiver and the KGC are reduced greatly. Bilinear pairing is employed in the many-to-one scheme and the definition of the bilinear pairing is recalled, and a concrete scheme is constructed based on its definition and security model. The security is also proven on the random oracle model. The legal senders can send eiphertexts with their encryption keys, and the receiver can decrypt them with his unique decryption key and verify the senders＇ identity. The encryption keys are derived from the information about the receiver＇s private key. The length of ciphertext is independent of the number of senders, i. e. , the length of the ciphertext is constant.