Zero-trust Enabled Anonymous Continuous Cross-Domain Authentication for UAVs: A Blockchain-Based Approach

The open and zero-trust nature of the heterogeneous low-altitude intelligence network requires more stringent secure authentication that cannot be meet with conventional schemes, due to the static authorization misalignment, long-validity token infiltration risk, and single-factor credential ossification. To address these challenges, this study proposes a blockchain-based cross-domain authentication scheme. We first develop a blockchain-enabled secure cross-domain registration and information management architecture incorporating a dual-index data structure for efficient historical query operations. Unmanned aerial vehicles (UAVs) achieve cross-domain registration through blockchain-based secure interactions with target domain trusted authorities (TAs). A cross-domain authentication protocol integrating physical unclonable function (PUF) and hash-based signature technique is designed, for mutual authentication. The TA generates time-limited cross-domain tokens with restricted communication attempts for UAVs, which subsequently establish negotiated session keys with base stations for secure resource sharing. To enhance security dynamics, both parties update temporary identity information and prepare fresh authentication keys during each token request cycle. The TA delegates token-updating random factors to base stations to ensure secure token renewal. Additionally, as the blockchain records the hash values of each token round, TA can detect if internal attackers have tampered with the token state. The security analysis and experiments demonstrate the advantages of our scheme.