Bitcoin’s strength comes from two areas: The decentralized nature of computers working together, and the encryption of the Bitcoins themselves. People often ask how secure Bitcoin is against super-computers, as well as the advanced Quantum Computers that are on the horizon. Since Bitcoin is based on computers working together, there is a lot of technology that goes into securing the data. Super-computers are measured by how much work they can do (the work is called ‘floating point operations’, or FLOP) every second. The work that computers do for Bitcoin is useless for anything else, so it isn’t very profitable to build a super-computer just for Bitcoin. An advantage of being decentralized is that Bitcoin is supported by anyone’s existing hardware, and all those individual computers add up. Currently, the biggest super-computer in the world can do 8.7 quadrillion flops, which is equal to 8.7 Petaflops. If you were to convert the average power of the current hardware supporting the Bitcoin network, Bitcoin would be a 107 Petaflop super-computer. By taking advantage of distributed computing power, Bitcoin is designed to stay ahead of the curve. Bitcoin is also protected from Quantum Computers, due to the particular encryption Bitcoin uses . In order to ‘crack’ even one Bitcoin wallet, it would take a Quantum Computer ‘one billion billion billion billion’ (2^128) pieces of work. For reference, the entire Bitcoin network has only done ‘one thousand billion billion billion’ (2^70) pieces of work in the two years Bitcoin has been operating. To compare that to something more familiar, there are only an estimated ‘million billion billion’ stars in the universe. A computer would have to do more work than there are stars in the universe just to crack just one wallet. The last possibility is that the encryption itself is ‘cracked’. Bitcoin is flexible and can be upgraded at any time, and it would take only a few days to distribute an upgraded Bitcoin around the world – though, during that time, wallets could be compromised. However, since this is the same encryption used by major banks and other payment methods, if the encryption itself were ever ‘cracked’, those institutions could be shut down and vulnerable for weeks. Bitcoin would be secure again within only hours or days. Of course, current protection won’t be enough forever, but the Bitcoin network grows as fast as the technology around us. Any situation requiring an upgrade to the network security can be done at a moments notice.