Can a publicly visible but privately mined block chain be trusted?

Question

Outside of Bitcoin, if a company set up a blockchain like structure that can be publicly accessed but only the company itself mines blocks, does that mean the blockchain can't be trusted?

I have only a rough theory in mind, no hard examples. Say a card game was implemented using a block chain. Card collections and game stats are stored in a blockchain and accessed by all the players of the game. None of the players mine any of the blocks. As players play the game, trade cards, open booster packs, etc they submit varying types of transactions to the company and the company verifies and adds the data to the blockchain. But the company mines the blockchain to solidify those transactions themselves and not allowing clients to mine at all.

I can see how money (Bitcoin, fiat, etc) would change hands for rare cards or booster packs. Inherently there would be value for the cards not unlike Magic: The Gathering or Pokemon having rare cards that people want. Can a player trust the company's blockchain? Since the number of miners is controlled by the company, what would be an acceptable difficulty for the miners to have to reach? Wouldn't too low of a difficulty not be enough proof of work to be trusted?

Since it's in the company's best interest to promote the proper use of the chain it's not really a 51% attack (technically a 100% attack). The users would know they're not mining from the beginning. Would this be any different than the company choosing postgres over MySQL? It's just the company's choice for storage, right?

Answer 1

I'm hoping that data transparency and data integrity can be preserved by having a publicly visible blockchain but since there's no reward to users for mining there's not much reason they will actually mine.

There's really no point. There's much simpler ways to provide the same data transparency and integrity guarantees. The only reason to use a blockchain would be so you could say "it's cool because we use a blockchain".

You can use transactions without a blockchain. You can map ownership to cryptographic identities without a blockchain. The sole miner just sign that it's accepted a transaction rather than doing anything like mining.

A blockchain doesn't do anything for data transparency. Just because you have a blockchain doesn't compel you to make it publicly accessible. And you can make data publicly accessible regardless of its format, blockchain or not.

And there's lots of costs associated with blockchains, none of which give any benefit. The whole point of mining is to allow you to determine what is truth without a central authority to say what is true. If you have that anyway, what's the point?

This is such an easy to solve problem and blockchains have such complex tradeoffs, it would really only make sense if you were too lazy to build something more appropriate and just happened to have a blockchain solution you could easily drop in.