An Efficient Real-Time Broadcast Authentication Scheme for Command and Control Messages

Broadcast (multicast) authentication is crucial for large and distributed systems, such as cyber-physical infrastructures (e.g., power-grid/smart-grid) and wireless networks (e.g., intervehicle networks, military ad hoc networks). These time-critical systems require real-time authentication of command and control messages in a highly efficient, secure, and scalable manner. However, existing solutions are either computationally costly (e.g., asymmetric cryptography) or unscalable/impractical (e.g., symmetric cryptography, one-time signatures, delayed key disclosure methods). In this paper, we develop a new broadcast authentication scheme that we call rapid authentication (RA), which is suitable for time-critical authentication of command and control messages in large and distributed systems. We exploit the semistructured nature of command and control messages to construct special digital signatures, which are computationally efficient both at the signer and verifier sides. We show that RA achieves several desirable properties that are not available in existing alternatives simultaneously: 1) fast signature generation and verification; 2) immediate verification; 3) constant size public key; 4) compact authenticating tag; 5) packet loss tolerance; 6) being free from time synchronization requirement; and 7) provable security.