# DCAGS-IoT: Dynamic Cross-Domain Authentication Scheme Using Group Signature in IoT
## 2 Related Work
[16] uploaded the hash value calculated by the certificate of the mobile device to the blockchain. During identity authentication, it is only necessary to verify whether the hash value of the certificate provided by the device is the same as the stored hash, avoiding the tedious verification process of the authentication mechanism. [PERSON] et al. [17] designed a secure cross-domain authentication and key agreement protocol for heterogeneous wireless networks with different security parameters based on blockchain. [PERSON] et al. [18] designed a user identity credibility initialization method by using the entropy-based probability weighted subjective trust and risk evaluation method for the user's identity credibility problem in heterogeneous domain cross-domain authentication. The trustworthiness of various users in heterogeneous domains was calculated and described. [PERSON] et al. [19] proposed a differentially private data flow system to address privacy issues in distributed edge computing. [PERSON] et al. [20] proposed a cross-domain identity authentication scheme for cloud service providers in different trust domains based on the group signature scheme, and used the Chinese remainder theorem to solve the problem where the traditional identity authentication model cannot be applied to cloud computing, which simplified the calculation process. [PERSON] et al. [21] analyzed and identified some serious security flaws in the SAKA-FCauthentication key exchange scheme and made improvements. [PERSON] et al. [22] proposed a secure message authentication protocol for information exchange between IoV entities based on secure symmetric lightweight hash functions and cryptographic operations. At the same time, most cross-domain authentication schemes only consider the situation that the device accesses other trust domains in the trust domain to which it belongs, and does not discuss the scenario where the device moves to other trust domains for resource access. In addition, many solutions do not involve the addition and deletion of users, and the efficiency of the solution will also decrease as the number of users increases, affecting the user experience. [PERSON] et al. [23] proposed a cross-domain certificateless authentication GKA protocol for 5G network slicings that supports dynamic group user management. This scheme requires only one round of communication and allows group users from different network domains with different cryptosystem parameters to jointly negotiate the group session key. [PERSON] et al. [24] utilized homomorphic encryption to solve the VANET cross-domain authentication problem under the new RSU edge network assumption to dynamically update anonymous vehicle identities. [PERSON] et al. [25] designed a blockchain-based authentication and key agreement protocol for the multi-TA network model, which shifted the computational load of the TA down to the RSU to improve the authentication efficiency. [PERSON] et al. [26] proposed a two-way anonymous traceability group authentication protocol in IoV, where the RSU in the group can anonymously trace the identity of malicious vehicles. The scheme uses the blockchain to quickly revoke their identity, and can also freely change the ID of users who reveal their true identities. [PERSON] et al. [27] allowed IoV nodes in a certificateless encryption (CLC) environment to send messages to servers in a public key infrastructure (PKI) environment to secure the communication between the server and the IOV. Since there is no paired computation, the protocol has an efficient advantage over existing protocols. [PERSON] et al. [28] proposed a new authentication scheme to jointly achieve effective authentication and partial trust management through scalability in a distributed IoT environment, but this scheme only considers user additions within a single trust domain.