Multimedia Broadcast Authentication Based on Batch Signature [Advances in Mobile Multimedia]

Conventional block-based broadcast authentication protocols overlook the heterogeneity of receivers in mobile computing by letting the sender choose the block size, divide a broadcast stream into blocks, associate each block with a signature, and spread the effect of the signature across all the packets in the block through hash or coding algorithms. They suffer from some drawbacks. First, they require that the entire block with its signature be collected before authenticating every packet in the block. This authentication latency can lead to the jitter effect on real-time applications at receivers. Second, the block-based approach is vulnerable to packet loss in mobile computing in the sense that the loss of some packets makes the other packets unable to be authenticated, especially when the block signature is lost. Third, they are also vulnerable to DoS attacks caused by the injection of forged packets. In this article we propose a novel broadcast authentication protocol based on an efficient cryptographic primitive called a batch signature. Our protocol supports the verification of the authenticity of any number of packets simultaneously and avoids the shortcomings of the block-based approach.