  In this article, the authors provide a comprehensive overview on three core
pillars of metaverse-as-a-service (MaaS) platforms; privacy and security, edge
computing, and blockchain technology. The article starts by investigating
security aspects for the wireless access to the metaverse. Then it goes through
the privacy and security issues inside the metaverse from data-centric,
learning-centric, and human-centric points-of-view. The authors address private
and secure mechanisms for privatizing sensitive data attributes and securing
machine learning algorithms running in a distributed manner within the
metaverse platforms. Novel visions and less-investigated methods are reviewed
to help mobile network operators and metaverse service providers facilitate the
realization of secure and private MaaS through different layers of the
metaverse, ranging from the access layer to the social interactions among
clients. Later in the article, it has been explained how the paradigm of edge
computing can strengthen different aspects of the metaverse. Along with that,
the challenges of using edge computing in the metaverse have been
comprehensively investigated. Additionally, the paper has comprehensively
investigated and analyzed 10 main challenges of MaaS platforms and thoroughly
discussed how blockchain technology provides solutions for these constraints.
At the final, future vision and directions, such as content-centric security
and zero-trust metaverse, some blockchain's unsolved challenges are also
discussed to bring further insights for the network designers in the metaverse
era.
