DynaTrac: A Decentralized Cross-Domain Authentication Framework With Dynamic Reputation Weighting and Accountable Tracing

The rapid growth of Internet of Things (IoT) boosts device connectivity but complicates cross-domain interoperability. Centralized authentication faces single-point failures, while blockchain’s decentralized, tamper-resistant nature overcomes these limits. Current work optimizes blockchain-based cross-domain authentication efficiency and user privacy, yet IoT’s dynamic environments require tailored mechanisms. To tackle these issues, we designed a decentralized cross-domain authentication framework, DynaTrac, with dynamic reputation weighting and accountable tracing mechanisms. DynaTrac uses Distributed Key Generation (DKG) and Aggregate Threshold Signatures (ATS) protocols to generate shared keys and signatures, avoiding the involvement of trusted third parties. In order to adapt the mobility of the device, we design a dynamic reputation-weighted DKG-ATS protocol to cope with the frequent entry and exit of IoT devices. This protocol dynamically adjusts the reputation and weights of the nodes based on behavioral metrics. The updated reputation weights govern nodes’ participation shares in key negotiation and authentication processes, effectively minimizing disruptions caused by low-weight devices. The framework employs authentication tokens, which are inspired by blockchain transaction structures, to enable efficient cross-domain verification. Additionally, a signature-based traceability mechanism embeds traceable tags into threshold signatures to ensure node anonymity during normal operations while enabling the identification of malicious behaviors. Finally, security analysis and simulation experiments validate the effectiveness of DynaTrac.