Is quantum computing a real threat to cryptocurrency?
Can the current encryption algorithms be broken with quantum computers? Will this be a danger to cryptocurrency?
Is quantum computing a real threat to cryptocurrency?
Can the current encryption algorithms be broken with quantum computers? Will this be a danger to cryptocurrency?
The answer irrelevant of how long it might take is yes. One key reasoning is from Forbes who says; “At a major crypto event at University of California Santa Barbara this week, Martinis talked about why it could take a decade or more to build a quantum computer. “This is really, really hard, way harder than building a classical computer,” he said.
He went on to explain to the packed room at Crypto 2017, a four-day conference sponsored by the International Association for Cryptographic Research, that the main reason building a quantum computer is so tough is because qubits (quantum bits), the counterpart of bits in classical computers, are unstable. And that creates extra work for physicists trying to solve the problem.”
Article link: https://www.google.com/amp/s/www.forbes.com/sites/amycastor/2017/08/25/why-quantum-computings-threat-to-bitcoin-and-blockchain-is-a-long-way-off/amp/
# Big picture
No matter what he said on the time needed to build these computers, one thing is clear. After the 10 years or so it will take to build, it can be destructive to a crypto currency. Remember that having 51% of the network hash, means that you are in control on the network. With these computers, the network can be overrun for malicious attempt, and once reaching 51% can be exposed badly. So no matter if it’s in a year, a decade or a century, there will be a time in the future when quantum computing can overrun crypto currencies.
I don't mean doing a 51% attack with a quantum computer rather use it to hack the encryption algorithm.
Well, actually your questions are being broken down into several somewhat relevant but not really wholly-related questions.
For the first question, no, quantum computing is not a real threat to cryptocurrency for the simple fact of the electricity cost.
Currently, in order be a real threat to cryptocurrency, one would need to accomplish the attack known as '51% attack'. Literally, from the coined term, we could know that the attacker need to control the simple majority (>50%) in order to launch an effective attack with interfere with the underlying blockchain. They can theoretically monopolize the creation of new blocks, which allow them to exploit the vulnerability of double-spending. But fortunately, this would need a large amount of computing power as well as electricity.
While quantum computer could possibly attain high computing power, and hence pose threats towards cryptocurrency. Let's not forget that quantum computer is made from specialized design consisting of superconductors (They need to be cooled to a outrageous level of -273°C, to function properly!). This would use a lot of electricity, hence render this threat currently impossible, at least from a technical perspective.
For the rest of the questions, they are more about the computational ability of the quantum computers, which the answer would be simply yes! But still, we still got a long way to go, and currently the biggest threat for cryptocurrency would be scalability. This deserves more attention, IMO.
I don't mean doing a 51% attack with a quantum computer rather use it to hack the encryption algorithm.
Yes, Quantum Computing might be a real threat to Blockchain as well as to Cryptocurrencies, according to MIT Technology. They said : "....this kind of computing can hack the cryptography hash that universally secures the Blockchain...."