What Will Happen to the Blockchain Industry When Quantum Computers Arrive?

Here's the thing: quantum computing has the potential to completely disrupt the security model of blockchain history. While today’s blockchains, such as Bitcoin, Ethereum, and Solana, are designed to withstand classical computer attacks, they cannot effectively resist attacks from powerful quantum computers. The very emergence of quantum computing can challenge the cryptographic foundation of blockchains for decades.

The good news is that the blockchain industry is highly unlikely to disappear. Why, you ask? Well, the technology is designed to evolve, adapt, and migrate towards quantum resistance with post-quantum cryptography. However, in the case of quantum cryptography, the blockchain industry may have to undergo the largest infrastructure upgrade in its history.

Today, let's talk about exactly what will happen to the blockchain industry when quantum computers arrive:

Why Quantum Computing Matters

We have discussed this in prior blogs as well. The problem is that most blockchains rely on public key cryptography to secure user wallets, verify identities, and validate transactions. While traditional cryptographic algorithms, such as ECDSA and RSA, are designed to solve mathematical problems that are computationally infeasible for classical computers to solve, quantum computers can break them with minimal effort.

Quantum computers use Shor's algorithms, which allow them to solve factorization and discrete logarithm problems at an exponential rate. As a result, the private keys of blockchain users can become vulnerable to the computational power of quantum machines.

Therefore, in the blockchain ecosystem, this capability represents a direct threat to digital asset ownership.

The Biggest Risk of Quantum Computing to the Blockchain Industry

Quantum computing has the power to completely reshape the foundations of blockchain security. Here's what we mean by that:

Compromising Wallet Security: 

Blockchain ownership for any digital asset is based on a private key. The problem is that quantum computers can derive the private key from a public key, and, therefore, in the wrong hands, this could mean a hacker gaining complete control of someone's crypto wallet funds. This risk is highly concerning for treasury reserves, high-value wallets, and institutional holdings. 

According to some cybersecurity researchers, millions of blockchain addresses could become vulnerable if quantum-safe blockchain solutions are not widely adopted before quantum computers mature.

Obsolete Digital Signatures: 

As we know, the current reality is that each blockchain transaction is verified via a cryptographic digital signature; this whole mechanism has the potential to become obsolete. Because quantum computers can break signature schemes, they can also enable fraudulent transactions through forged signatures, undermining trust in blockchain networks. Of course, without secure digital signatures, the fundamental integrity of blockchains would also become unreliable and difficult to maintain.

Long-term Data Protection: 

We talk about the concept of 'harvest now, decrypt later' very commonly..and it is a huge problem. See, if attackers can collect encrypted blockchain-related data today and store it until later to use when quantum computers arrive, this could expose historically sensitive information. Dealing with this challenge requires blockchain organizations to evaluate risks and implement safeguards before practical quantum attacks even become feasible.

Vulnerabilities in Smart Contracts: 

Currently, blockchain smart contracts rely heavily on cryptography for access control, verification, authentication, and even authorization. As quantum capabilities advance, it will become a problem for organizations, with the impact potentially extending to DAO governance systems, DeFi platforms, cross-chain bridges, NFT ecosystems, and even tokenized asset networks. 

This also means smart contracts could become susceptible to exploitation, which can cause significant disruption to operations for the entire ecosystem.

Can Quantum Computers Break Bitcoin, Ethereum, or Other Blockchains?

One of the most frequently asked questions is this... and the answer is: not necessarily. Of course, there is a strong quantum computing threat to Bitcoin and other blockchains. But these blockchain networks are software systems, which means they can be upgraded. 

Take the example of Ethereum; it can be used with ARMchain via cousin approach to offer its users a quantum-resistant blockchain experience.

What is ARMchain, you ask? 

ARMchain is a quantum resistant blockchain that works as an L2 security layer to offer post-quantum security for Ethereum ecosystems. Since it is an EVM-compatible blockchain, it allows developers to transition gradually without having to rewrite their existing applications from scratch. 

So, organizations can migrate security-sensitive dApps that require quantum resistance to ARMchain and continue to operate their non-quantum functions normally on Ethereum while selectively integrating this quantum-resistant blockchain’s features as needed.

Even if you are not considering ARMchain and are hoping that current mainstream blockchains will catch up to post-quantum standards, migration is still possible. The challenge is not technical feasibility but coordinating upgrades for millions of users and applications across decentralized ecosystems so that networks can transition without disruption.

The Rise of Post-Quantum Cryptography and Its Effect on the Blockchain Industry

Post-Quantum Cryptography (PQC) is a class of algorithms designed to keep data secure against attacks by both classical and quantum computers. PQC uses mathematical problems to secure communications, making it resilient against quantum attacks. Therefore, post-quantum cryptography is essential for quantum computing and blockchain while remaining compatible with existing cryptographic environments.

Types of Post Quantum Cryptography Algorithms

It is important to understand that post quantum cryptography is not a single method or algorithm. Instead, it is a conglomerate of five different cryptographic approaches used in a post-quantum blockchain to resist quantum attacks on both classical and quantum computers. This classification is similar to grouping based on hardness assumptions of the mathematical problems for which security is defined. Let's explore these approaches one by one:

1. Lattice-Based Cryptography:

First and foremost, lattice-based cryptography is the most studied and most promising category of post quantum cryptography algorithms. It uses mathematical lattices with high-dimensional structures to build cryptographic security. These lattices are complex geometric structures that serve as the foundation for modern encryption schemes, making even quantum computers struggle to solve them.

ARMchain also uses MLDSA, a lattice-based digital signature scheme, for the security layer of its algorithm. This integration allows our systems to operate securely with quantum-resistant cryptography. As a result, users can transact with a high level of post quantum security.

2. Hash-Based Cryptography:

Hash-based cryptography is a new form of cryptography that relies on cryptographic hash functions to generate digital signatures rather than on algebraic structures. The security of this approach is strong because it relies on the difficulty of reversing hash functions or finding collisions.

This approach is considered highly secure for any post-quantum blockchain, but hash-based systems can have their own limitations, such as larger signature sizes or restricted use cases, which have limited wider adoption in this category.

3. Code-Based Cryptography:

Code-based cryptography is a scheme that is built on the difficulty of decoding random error-correcting codes. An interesting fact about these is that they have been studied for decades, since the 1970s, and are widely believed to remain resistant even in the quantum era.

However, due to the large key sizes of these systems, code-based cryptography has never really achieved mainstream adoption. Nonetheless, it remains an important candidate for post-quantum security.

4. Multivariate Polynomial Cryptography:

MPC cryptography is highly interesting because it uses multivariate polynomial equations to solve hard mathematical problems for secure encryption and signatures. These systems are computationally very hard and resistant to classical attacks. However, many multivariate schemes have been broken by cryptanalysts over time, leaving this category more experimental than lattice or hash-based systems.

5. Isogeny-Based Cryptography:

Isogeny-based cryptography is a relatively new form of cryptography. It is an emerging field and is in its experimental phase. This approach relies on mathematical relationships between isogenies of elliptic curves.

When it comes to quantum computing and blockchain, the PQC algorithm, is considered promising due to its small key sizes, but over the years, some proposed systems have been broken. Research in this area is ongoing, but it could be an interesting direction for post-quantum cryptography.

What Changes Can We Expect in the Blockchain Industry?

As the blockchain industry prepares to adapt to a quantum future, we can expect to see:

1. Blockchain Protocol Upgrades: Networks may move from classical cryptography to post-quantum cryptography and introduce new signature protocols, such as lattice-based cryptography and hash-based signatures, through hard forks to replace vulnerable elliptic curve cryptography algorithms.
2. Wallet Migration Campaigns: Crypto users may begin moving their digital assets from legacy wallets to MPC-based, quantum-resistant wallets specifically designed to withstand quantum threats.
3. New Quantum Safe Blockchains: Innovative quantum-safe blockchains, like ARMchain, will start appearing on the horizon - offering security with post-quantum cryptography built into the very foundation of decentralization.
4. Regulatory and compliance Pressure: Global governments and institutions are already moving towards quantum readiness. This pressure may increase to the point of mandates and impose requirements on enterprises.

Final Words

As the quantum era unfolds, we can clearly see that quantum computers could destroy blockchain overnight. Luckily, the blockchain industry is not just a technology; it is a collection of software systems capable of upgrading themselves. The challenge here is that the threat from quantum computing is not a minor risk; it demands a complete upgrade of the cryptographic infrastructure, which will require blockchain networks to migrate.

For crypto users, there is an important opportunity to look for quantum-safe blockchains, such as ARMchain, that are built on PQC and designed as a foundational layer rather than just an incremental upgrade. Blockchain networks already in the ecosystem need to prepare early for this transition so they can be better positioned to protect digital assets and maintain client trust.

At the end of the day, the quantum era won't be the end of the blockchain industry. But it surely will be the end for networks that do not take this looming threat seriously. For the rest, it will surely be the next era of decentralization.

Frequently Asked Questions (FAQs)

Can quantum computers break Bitcoin?

Yes, in theory. If quantum computers become practical before Bitcoin has prepared to transition to a quantum future, it can be compromised. However, large-scale blockchain networks are already preparing to upgrade their infrastructure, so we can hope that it won’t happen.

When quantum attacks happen, which part of modern blockchains will be most at risk?

The most vulnerable component of blockchains will definitely be public keys, especially those used for digital signatures, wallet private key protection, and smart contracts.

Can Bitcoin and other cryptocurrency systems be upgraded to resist quantum attacks?

Yes, blockchain networks can adopt PQC through soft/hard forks and protocol upgrades. The process would involve replacing ECDSA with post-quantum signatures and private keys with quantum-resistant ones to ensure transaction security.

Should crypto users worry about quantum computing right now?

Google has already announced Q-day, which means it will take another half-decade for quantum computers to become practically viable for cryptographic attacks. The threat is not immediate for users. However, long-term crypto holders and institutional organizations should start preparing for migration to post-quantum cryptography.