That is given that the data remains true at the point of data entry into the network. If the data entering the chain is bogus due to bribery, blockchain won't solve the problem.
I think that's addressing a different problem. There are two distinct issues:
1. Is the data correct?
2. Has the data been changed?
For many cases, 1) is not solvable in software.
I'm not sure I really understand why 2. is something best solved with a blockchain with a private group, but given people who have actually looked into this when I haven't think it's relevant means I'm probably missing something either on the requirements, difficulty to implement or features.
