With the rapid advancement of Internet of Things (IoT) technology, ensuring secure communication among resource-constrained devices has emerged as a critical challenge. Traditional group key distribution schemes fail to effectively handle the dynamic nature of IoT environments, characterized by frequent node join and leave events, and often struggle to balance security with performance. Addressing these limitations, this paper proposes a novel group key distribution scheme integrating blockchain technology with quantum key cloud servers. Leveraging the decentralized trust and smart contract capabilities inherent to blockchain networks, the proposed method provides efficient and reliable key management. The incorporation of quantum key cloud servers ensures high security and randomness of distributed keys. Furthermore, the paper innovatively combines Elliptic Curve Cryptography (ECC) with Chebyshev chaotic mappings to develop a novel digital certificate generation mechanism and an encrypted transmission verification method, significantly enhancing the system’s resilience against attacks. Through formal security analyses and performance evaluations, the proposed scheme is demonstrated to be effective and advantageous within real-world IoT contexts.

The twenty-first century has been dominated by the need for large scale data processing, marking the birth of big data platforms such as Cosmos. This paper describes the evolution of the exabyte-scale Cosmos big data platform at Microsoft; our journey right from scale and reliability all the way to efficiency and usability, and our next steps towards improving security, compliance, and support for heterogeneous analytics scenarios. We discuss how the evolution of Cosmos parallels the evolution of the big data field, and how the changes in the Cosmos workloads over time parallel the changing requirements of users across industry.