A group key management scheme based on distributed Path Computation Element (PCE) architecture was proposed aiming at the communication characteristics and key management requirement of multi-domain optical networks in PCE architecture. Firstly, the key relation of multi-domain optical network under distributed PCE architecture was modeled as a two-layer key hypergraph by using hypergraph theory. Then, the key management method based on self-authenticated public key cryptosystem and member filtering technique was adopted in the autonomous domain layer and the group key agreement method based on elliptic curve cryptosystem was adopted in the PCE layer. Finally, the generation, distribution, update and dynamic management of the key were completed, and the confidentiality problem of the private key of member and the impersonation problem of the third party node were well solved. At the same time, the computational overhead of key update was reduced. The performance analysis shows that the proposed scheme has forward security, backward security, private key confidentiality and is against collusion attack. Compared with the typical decentralized scheme, the proposed scheme achieves better performance in terms of key storage capacity, encryption/decryption times and communication overhead.

Concerning the inefficient time performance and lower clustering accuracy revealed by the traditional density-based algorithms of DBSCAN and DBRS, this paper proposed an improved density-based clustering algorithm called DBLRS, which is combined with limited regional sampling technique. The algorithm used the parameter Eps to search for the neighborhood and expanded points of a core point without increasing time and space complexity, and implemented data sampling in a limited area (Eps,2Eps). The experimental results confirm that DBLRS can reduce the probability of large clusters' splitting and improve the algorithmic efficiency and clustering accuracy by selecting representative points to expand a cluster.