October 26, 2019 Update on Google’s quantum supremacy breakthrough.

Following leaked discussion last month, Google officially announced a 54-qubit quantum processor called Sycamore which executed a computation in 200 seconds that would take a leading supercomputer 10,000 years. Many observers have noted the potential implications for blockchain technology, particularly the possibility of breaking hash algorithms such as SHA-256 which underpin cryptocurrencies. However, Google’s development does not appear to pose an eminent threat, and was more narrowly targeted at other classes of applications. Per Vitalik Buterin: “My one-sentence impression of recent quantum supremacy stuff so far is that it is to real quantum computing what hydrogen bombs are to nuclear fusion. Proof that a phenomenon and the capability to extract power from it exist, but still far from directed toward useful things.”