Blockchain
Quantum Computing Threat to Blockchain Security: Expert
Quantum computing, once a theoretical concept, is now rapidly advancing and reshaping our understanding of data processing.
Unlike traditional computers that use bits, quantum machines use qubits, which can exist in multiple states at once. This makes them significantly more efficient than traditional computing systems when tackling complex problems.
For the blockchain sector, the rise of quantum technology poses a significant threat to cryptographic systems that underpin the security of the blockchain. Current cryptographic methods, such as Rivest-Shamir-Adleman (RSA) and Elliptic-Curve Cryptography (ECC), are widely used in networks such as Bitcoin AND Ethereal.
Their main strength lies in their complexity, which traditional systems cannot decipher. Yet quantum machines they claim they can break these systemspotentially making these networks vulnerable to attacks once thought unlikely.
With the entire industry including cryptocurrencies, non-fungible tokens (NFTs) and decentralized applications (DApps) at risk, quantum-resistant cryptographic measures are urgently needed. While slowly moving towards the post-quantum erathe blockchain industry must innovate and adapt.
To shed some light on these issues, Lisa Loud, executive director of the Secret Network Foundation and chair of the IEEE SA Quantum Algorithms Workgroup, recently spoke with crypto.news, discussing the implications of quantum computing for blockchain security and how these threats are being addressed.
What are quantum computer attacks and why are they considered a threat to blockchain and cryptocurrencies in general?
Quantum computing attacks are somewhat similar to today’s brute force attacks in that their ability to try different combinations has improved dramatically over classical computers. If you have a three-digit combination lock, there are about a thousand combinations, and a patient thief could try all of them and unlock your suitcase or steal your bike. When you have a 12-character online password, the permutations increase to 7,212 different possible passwords, which a human couldn’t handle, but a classical computer could try them all in sequence and eventually find the right combination. If you have a wallet with an encrypted private key, the number of possible options increases to 2,256. That’s too many for classical computers to handle, but a quantum computer could.
This is a simplification of reality, but it conveys the idea of why a quantum computer attack is a threat to blockchains and cryptocurrencies. Many proposals to address this threat are largely theoretical or rely on the solution of creating new blockchains with built-in quantum resistance, but this is not practical when there are millions of dollars locked in existing blockchains. Instead, some researchers are focusing on end-to-end frameworks that can be applied to existing blockchains. 3 Another less obvious but potential threat is that quantum computers may be able to mine blocks much faster than classical computers, potentially centralizing mining power.
Can the blockchain industry address these issues before quantum computing technology is fully ready?
These are the problems we see today, but who knows what will emerge when quantum computing becomes a reality. We know that blockchain cryptography is evolving specifically to counter these threats, but the bigger question is: what haven’t we thought of? What threats exist that aren’t obvious today but will only emerge when we have these two technologies in the same space? We don’t know the answer, but we can be sure of one thing: there will be new and unexpected problems to solve when blockchains meet quantum computing.
In theory, quantum computers can break RSA and Elliptic Curve cryptographic algorithms; how imminent is this threat to current blockchain platforms like Bitcoin and Ethereum?
The field of quantum cryptography, while promising in its potential to crack existing ciphers, is far from ready for practical implementation. At the same time, on-chain cryptography continues to evolve, and today’s cryptographers are aware of the quantum threat on the horizon. As a result of this set of conditions, the development of new on-chain cryptography methods considers quantum-proof methods necessary. Today, there is no imminent threat to Bitcoin or Ethereum simply because quantum hardware remains largely a theoretical construct.
Do you think cryptographic standards can help protect blockchain networks from quantum threats? Can they be integrated into existing systems like Bitcoin and Ethereum?
There are several cryptocurrency algorithms designed to handle quantum resistance, such as SPHINCS+. While I chair a standards committee at IEEE to define best practices in writing quantum algorithms, there are other working groups at IEEE and many other standards organizations working on best practices for developing quantum-resistant software. Blockchains will be able to switch cryptographic algorithms sooner than many other areas of the industry. In particular, chains that have a governance structure in place will have an easier time making the switch. Chains like Bitcoin or Ethereum may take longer.
What are the challenges decentralized blockchains face as they migrate to post-quantum cryptography? Is the pseudonymity inherent in public blockchains a problem?
Blockchain user pseudonymity is not so much the issue here as the distribution of nodes on each blockchain, of which Bitcoin is the most extreme. Any mitigation strategy to make Bitcoin quantum-proof will almost certainly require a change to the wallet address format. Bitcoin’s proof-of-work consensus mechanism is less immediately threatened, but its address system (based on ECDSA – Elliptic Curve Digital Signature Algorithm) is vulnerable and will need to change. This has historically been a messy process that has created chaos and some losses. Ethereum faces similar challenges with its address structure and widespread distribution, but has the advantage in that it is more easily upgradeable than Bitcoin due to its smart contract capabilities.
So yes, there will be challenges in migrating any blockchain to post-quantum cryptography, and the wider the chain distribution, the more difficult it will be to overcome these challenges. Wallets that are slower to migrate may face greater vulnerability to quantum attacks. Ensuring that post-quantum systems can interoperate with legacy systems during the transition period will require maintaining dual systems for an extended period, and the larger key structure may impact blockchain performance.
So are there blockchain networks equipped for this transition?
Some more recently built blockchains have an easier path to mitigation. For example, Cosmos is configured to be easier to migrate. All chains built on the Cosmos SDK may want to choose a common quantum-proof algorithm to simplify wallet integration. Some chains are specifically designed to encrypt the data they carry in transactions, such as Secret Network and Fhenix. Secret uses secure hardware enclaves (such as Intel SGX’s TEE) to protect encrypted data on-chain. These ciphers are resistant to quantum attacks because the secure enclaves can change their encryption schemes on the fly, which can have some performance implications. Fhenix uses mathematics, or fully homomorphic encryption, to protect data in a complex encryption scheme that is quantum-resistant. The technology for FHE is not ready for deployment today, but its timeline is much shorter than that of quantum computers. This allows the future of blockchains to be realized natively, with quantum resistance built in, long before quantum computing is ready to attack blockchains.
How long does the blockchain industry have before the threat of quantum computing becomes inevitable?
Within the next 10-20 years, the [blockchain] The industry should be fully prepared. Many experts believe that quantum computers capable of breaking current cryptosystems could emerge in this timeframe. Beyond that, if left unaddressed, quantum computers will likely be able to break most current cryptosystems used in blockchains. The day when quantum computing threatens the encryption of Bitcoin and Ethereum is in the uncertain future. As for when a computer with sufficient hardware and software to handle complex problems will be ready, based on modeling the number of qubits developed since 2014 and projecting that timeline forward1, early estimates are 2035, with some saying much later, as late as the year 2050.