Multicast Authentication over Lossy Channels

Authentication is critical to ensure the origin of a multicast stream. To avoid computationally expensive signature operations on each packet, conventional schemes divide a multicast 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 chains or codes. However, most of them suffer from drawbacks such as vulnerability to packet loss and authentication latency at the sender and/or receivers. Unlike the block-based approach, we develop a novel Multicast Authentication scheme based on Batch Signature (MABS). In particular, each packet is attached with a signature, and a receiver authenticates any number of packets simultaneously by verifying their signatures through only one verification operation. We propose three implementations of MABS including two new batch signature schemes based on BLS and DSA and show they are more efficient than the batch RSA signature scheme. MABS is perfectly resilient to packet loss and completely eliminate the authentication latency at the sender and receivers.