Nearly all personal information is stored electronically in our digital age. This sensitive data is protected by digital keys unique to each device that would take today’s computers billions of years to crack through brute-force hacking attacks.
But technology evolves. So what happens when new technology can break those keys in a matter of hours? With powerful quantum computers in development, this “quantum decryption” is a very real possibility in the future.
Associate professor of computer science Abdullah Aydeger was a member of the team led by Ahmet Kurt, an assistant professor from East Texas A&M University, that created a new way to keep the keys on the Bitcoin Lightning Network secure against quantum computers.
The paper, “PQLN: Post-Quantum Security for the Bitcoin Lightning Network’s Off-Chain Surfaces,” was published on arXiv, the online repository of pre-print scholarly articles, in September. It described changes to the Lightning Network’s software that add new protections against quantum computers that could break today’s keys.
The team focused on the lightning network as a proof of concept because its software can be changed without having to change Bitcoin itself, which would require getting every separate computer on the blockchain to run a new code.
“It’s still secure, you’re not really eliminating the security or the consensus behind the transaction,” Aydeger said. “You just don’t have to wait for the whole network to check every small payment. The money is still locked up on the blockchain, and either side can go back to it at any time.”
With a market capitalization of around $1.6 trillion, Bitcoin has become a major financial pillar. Bitcoin runs on a blockchain network, meaning each transaction is independently verified by thousands of computers. Atransaction on the blockchain network can take as long as an hour to be verified. On the faster lightning network, that can happen in under a second, making that network ideal for small payments and transactions.
Protecting authentication keys is very important because the key proves you own your crypto wallet. If someone gains access to it, they can spend or transfer the money in your wallet or pose as the owner without ever touching your device.
That’s why this team is building future-proof security measures, knowing the technology to break the current keys is coming. “We cannot wait to have it, because once it’s broken it’s too late to fix something,” Aydeger said.
The goal of this project was to create new protections for the lightning network to protect the security keys from Shor’s algorithm, which has existed for over 30 years without a quantum computer big enough to run it. Security keys lock data by multiplying two incredibly large prime numbers to create an even larger number, which is very easy for computers to do.
Shor’s algorithm can solve the equation in reverse, working backwards from the final number to find the original prime numbers, a calculation too complex for current computers to run efficiently.
Our computers now can attempt to brute force the current keys by guessing each combination of binary data one at a time, but it would take them billions of years. A quantum computer running Shor’s algorithm doesn’t have to guess at all and can find the pattern needed to break the key in a matter of hours.
Cryptocurrencies have a unique shortcoming that can make cyberattacks particularly damaging to users. Standard bank accounts typically offer insurance against fraudulent transactions, but Bitcoin is decentralized and transactions are irreversible, making it nearly impossible to recover stolen funds.
The fraudulent transactions don’t even require a quantum computer to run. Once a quantum computer breaks the key, transactions can be made from any computer. That is why it is so important to protect these security keys, since once they are broken it would make stealing funds and impersonating wallet owners much easier for hackers.
