This is interesting stuff, but it&#x27;s still a stop gap. As you say, large solo miners are an ongoing concern.<p>If bitcoin ever makes it big, IMO, it&#x27;ll be large corporations running mining operations. Just as the general population does most of its services through huge corporations, mining bitcoin will probably be done by them as well.<p>What do you think of Proof of Stake systems? Are they feasible? I&#x27;m working on one, btw, with a shared spending pool and an ability to vote to spend the pool, and to change the code of the official client, thereby changing the rules of the system.