But the last one is the most interesting to finally be able to trust the results. It's the same problem as faced in distributed systems, but in, say, NoSQL data

But the last one is the most interesting to finally be able to trust the results. It's the same problem as faced in distributed systems, but in, say, NoSQL databases I haven't heard anyone consider the possibility of 4 of 6 members of a quorum to be undermined, and how to detect that.