## 5 Use Case of 6G-OPENSEC-Security  
In the ever-evolving landscape of telecommunications, driven by the advent of 6G and the increasing demand for ultra-fast and highly reliable connectivity, security has emerged as a critical priority. With the proliferation of connected devices and the growing virtualization of network infrastructure, ensuring data integrity, confidentiality, and availability has become a complex and multifaceted challenge. In this scenario, which has already been mentioned, the traditional approach to security, based on static and reactive measures, is no longer adequate to address today's dynamic and sophisticated threats. There is a need to adopt a more agile, proactive, and adaptable approach to ensure the proper protection of network resources and sensitive user data. This section aims to explore the use cases and applications of dynamic security service provisioning as an effective response to emerging challenges in network-slicing environments. Through the analysis of concrete cases and specific use scenarios, it will be examined how dynamic security service provisioning can enhance security in network slicing, ensuring robust and adaptable protection in the face of evolving threats. In particular, the focus will be on the crucial role of a Security Closed-Loop (SCL) as a fundamental component in dynamic security service provisioning, highlighting its essential functionalities and its impact on ensuring security in network slicing. One project being developed is 6G-OPENSEC. This project aims to deliver security, trust, and quantum critical distribution solutions designed for 6G transport networks, employing an open and adaptable architecture. This project is divided into three projects: 6G-OPENSEC-SECURITY ([[https://www.cttc.cat/project/secure-network-slice-manager-for-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/secure-network-slice-manager-for-open-and-disaggregated-6g-networks/)]([https://www.cttc.cat/project/secure-network-slice-manager-for-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/secure-network-slice-manager-for-open-and-disaggregated-6g-networks/)) (accessed on 29 April 2024)), 6G-OPENSEC-TRUST ([[https://www.cttc.cat/project/dlt-based-trust-management-for-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/dlt-based-trust-management-for-open-and-disaggregated-6g-networks/)]([https://www.cttc.cat/project/dlt-based-trust-management-for-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/dlt-based-trust-management-for-open-and-disaggregated-6g-networks/)) (accessed on 29 April 2024)), and 6G-OPENSEC-KEYS ([[https://www.cttc.cat/project/quantum-key-distribution-for-security-in-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/quantum-key-distribution-for-security-in-open-and-disaggregated-6g-networks/)]([https://www.cttc.cat/project/quantum-key-distribution-for-security-in-open-and-disaggregated-6g-networks/](https://www.cttc.cat/project/quantum-key-distribution-for-security-in-open-and-disaggregated-6g-networks/)) (accessed on 29 April 2024)). Since the security aspects of these upcoming networks have been discussed, our focus will be on 6G-OPENSEC-SECURITY. It promotes network management and security automation by following ETSI's standardised ZSM architecture. Also, it proposes a security model designed in a Closed-Loop architecture, which has been showcased in the work of [112], enabling not only the automation of network management in terms of resources and deployment as well as security features that are enforced via network policies. This automation not only reduces the complexity of management and security tasks from the operator's point of view but also the possibility of human error present in previously employed architectures that did not rely as much on automating tasks. Indeed, this automation does provide some new challenges in terms of reliability; however, this is why a Closed-Loop architecture was chosen when applying security.