A Lightweight Certificate-Based Source Authentication Protocol for Group Communications in Hybrid Wireless/Satellite Networks

In this paper, we describe an efficient authentication protocol for group communication in hybrid wireless networks with a satellite overlay. The proposed protocol uses a new class of lightweight, symmetric-key certificates called TESLA certificate. The certificates bind the identities of the senders to the anchor elements of their key chains; messages from the senders are authenticated by MACs computed with keys from the chain. The satellite is used as the certificate authority to generate the certificates. The satellite also acts as the proxy for the senders in disclosing the MAC keys to the receivers in the network. Due to the use of symmetric MAC functions, the proposed protocol is much less expensive in terms of node processing power and energy compared to digital signatures. The use of the satellite as the CA and the proxy allows strong security mechanisms and fast message verification. Through analysis, we show that the protocol is secure against malicious adversaries. We also estimate of the performance of the protocol in comparison to public key-based digital signatures.