The emergence of 6G networks introduces novel use cases such as holographic communication and autonomous driving. To meet these ambitious requirements, 6G is expected to adopt decentralised architectures that enhance performance by bringing computation closer to the user. However, this shift also introduces new security challenges, as the increased distribution of network components makes it harder to detect threats, prevent unauthorised access, and respond effectively to vulnerabilities. In this context, Security-as-a-Service (SECaaS) presents a promising solution by allowing enterprises to outsource their security operations to specialised providers. Yet, while most existing research focuses on SECaaS within centralised cloud environments, little is known about how it must evolve to address the unique demands of decentralised 6G networks. This thesis investigates how network decentralisation influences value co-creation among SECaaS stakeholders and explores its impact on the antecedents of customer trust. Drawing on ten qualitative interviews with experts from the telecom, infrastructure, and security sectors, the study applies the Value Network Configuration framework and the Integrative Model of Organisational Trust.

Findings reveal that decentralised 6G networks enable more distributed value co-creation, potentially even independent of the Mobile Network Operator. However, these deployments require enhanced stakeholder coordination to ensure secure service delivery meets customer expectations. While decentralisation does not significantly alter the core antecedents of customer trust, it can indirectly enhance relational trust through greater proximity, customer intimacy and contextual understanding. The study outlines key responsibilities across four stakeholder groups, identifies emerging trust-related factors such as regulatory compliance and geopolitical influences, and offers strategic recommendations for firms developing viable SECaaS business models in next-generation mobile networks.