Abstract: Networks coding is highly susceptible to pollution attacks，but such attacks cannot be prevented by the standard technology of signature. Based on the vector hash which is secure if the discrete logarithm problem is infeasible，an efficient signature scheme for securing two-source networks coding against pollution attacks was proposed. In this scheme, each source node signed the files with its own private key, the intermediate nodes, with the merge algorithm, produced linear combinations of vectors from different files. The intermediate nodes could verify the received signature solely by the public key. The security of signature scheme relies on the hardness of the Co-Deffie-Hellman problem. Under the random oracle model, the new scheme is proved to be secure against the source nodes and intermediate nodes attacks.

Key words: two-source network coding, Hash function, bilinear pairing, coding coefficient, discrete logarithm

摘要： 网络编码易遭受污染攻击的破坏，而传统的签名技术不能适用于多源网络编码。基于一种离散对数问题安全的向量哈希函数，提出一种有效抵御污染攻击的双源线性网络编码签名算法，方案中每个源节点用自己的私钥对文件签名，中间节点可用向量的合并算法线性组合来自不同源的消息，且中间（信宿）节点仅用公钥就可验证收到的签名。方案的安全性依赖于Co-Diffie、Hellman问题，并在随机预言模型下，证明能够抵抗信源节点和中间节点的攻击。

关键词: 双源网络编码, 哈希函数, 双线性对, 编码系数, 离散对数