Just came across this interesting blog from MIT Business Review about the security of block chain. We expect block chain to be the most secure and cannot be hacked by attackers, what about quantum computers with super specs who can reverse engineer the encryption within seconds during early faces of each crypto transaction. With the commodity hardware becoming cheaper day by day. Its becoming more easy to setup supercomputers, although, they not are commercialized to an extend where two guys in a garage can spin it up. But that day it not far and since so much promise is being delivered to the world about this technology we need to think securing it in any way possible.
[Read more here:] https://www.technologyreview.com/s/608041/first-quantum-secured-blockchain-technology-tested-in-moscow/