For a business use case I am conceptualizing for my master's thesis, wich is based on a Blockchain system, I need to understand impacts on decentralization/trustlessness.
Many people argue that private instances are utter nonsense, and you might as well use centralized databases because you need some kind of access control to let parties join the network and therefore and central entity controls it all. In my case, a consortium of three companies would set up a private Blockchain for confidentiality reasons.
Question: How to implement access to permissioned/private/consortium Blockchains in a decentralized or at least democratic manner?
If the nodes and their respective network addresses are defined contractually, let's say each stakeholder sets up 3 nodes, I don't see the need need for a central gate keeper. A befriended ethcore dev told me that still anybody could join the network an compromise it, yet I don't know how and why. Alternatively, I could imagine staking as Sybil-control where each member gets an equal share.