The offers that appear in this table are from partnerships from which Investopedia receives compensation. Blockchain How does a block chain prevent double-spending of Bitcoins? Vice versa, if the mining power decreases, a decrease of the mining difficulty can keep the block time roughly constant. The Verge. They felt as though SegWit2x did not address the fundamental problem of scalability in a meaningful way, nor did it follow the roadmap initially outlined by Satoshi Nakamoto, the anonymous party that first proposed the blockchain technology behind cryptocurrency.