How does the access protocol work?

As a cryptocurrency enthusiast and investor, I'm always curious about the technical aspects of various blockchain-based systems. Specifically, I'm interested in understanding how the access protocol functions in these systems. Could you elaborate on the key components of the access protocol? I'm wondering about how it authenticates users, manages permissions, and ensures the security of transactions. Additionally, I'd like to know if the access protocol is decentralized or relies on a central authority for authorization. Any insights you can provide would be greatly appreciated.