Today, the Bitcoin network's security, using a cryptographic algorithm called SHA-256, would be insurmountable for a computer as we know it to crack. But quantum computing may change that within the next decade. Scientists at the University of Sussex now estimate that quantum computers are likely to become powerful enough to crack the security that protects Bitcoins sometime in the next decade. New Scientist (opens in new tab) first reported on the study.
Bitcoin is based on a blockchain, essentially a ledger of who owns what, protected by the SHA-256 algorithm. If you could crack the key revealed during Bitcoin transactions, you could change ownership of a Bitcoin. The Sussex scientists, led by Mark Webber, explain that every Bitcoin transaction is assigned a cryptographic key, which is vulnerable for a finite time, which might vary from 10 minutes to an hour, to a day.
The researchers estimate that a quantum computer with 1.9 billion qubits would be necessary to crack a Bitcoin's encryption within 10 minutes. To manage the feat within an hour, a machine with 317 million qubits would be required. However, if you had a full day to try and crack the security, a system packing just 13 million qubits would be capable of the task.
Right now, the most potent quantum computer, developed by IBM, boasts 127 qubits. We are obviously a long way from machines with 13 million qubits becoming available, and a 317 million+ qubit machine is a much better bet in practical cracking of Bitcoins, as things stand. The Sussex scientists reckon that with the pace of advances we see now, sufficiently powerful quantum computers will not be realized for "potentially over a decade," putting us firmly into the 2030s.
Any projected calamitous D-Day for Bitcoin is very much a moving target. The scientists note that the Bitcoin network "could nullify this threat by performing a soft fork onto an encryption method that is quantum secure, but there may be serious scaling concerns associated with the switch." On the other side of the tug-o-war, developments in quantum computing could easily accelerate progress towards being able to hack Bitcoin security. The researchers mention the potential of trapped ion-based quantum computers, for example.
Indirect Attacks Are Growing in Popularity
Absorbing the huge numbers discussed by the scientists, plus pondering over concepts of quantum supremacy and quantum advantage, it is easy to forget that the current tech news landscape is littered with news of various crypto currencies and exchanges being hacked, or investor or speculator funds being otherwise purloined. How is this happening with such strong encryption deployed?
Any secure system is only as secure as its weakest point, as were were reminded by the very recent Wormhole crypto hack. Earlier today we reported that Wormhole, one of the most popular bridges linking the Ethereum and Solana blockchains, leaked $320 million to hackers. Blockchain protocols like Wormhole are necessary to the system for cross currency transactions, and other purposes, but have become an increasingly popular target in recent months.