Blockchain is the basis of numerous technologies, including cryptocurrencies like Bitcoin and Ethereum, safe electronic contracts, supply chain tracking, and more. It's very secure because it's based on complex mathematical puzzles that are very difficult for regular computers to solve. But with the advent of a new type of computer—a quantum computer—this security might be broken in the future.
What is Quantum Computing
So that we understand the threat that it poses; first, we must know what quantum computing is. While classical computers work on bits (0 or 1), quantum computers work on quantum bits, or qubits. Qubits are 0 and 1 at the same time based on something known as superposition. This allows quantum computers to compute information at incredibly rapid speeds and solve issues that will take classical computers millions of years.
Why Does This Matter for Blockchain?
Blockchain is very much dependent on cryptography for keeping information safe. One of the most popular techniques is public key cryptography. Essentially, this technique employs two keys—a public key for everyone to view and a private key known only to the owner. To access your blockchain information or cryptocurrency wallet, they would have to discover your private key, which is virtually impossible with today's computers.
But quantum computers will be so strong that they could possibly break this kind of encryption. A quantum computer could, in theory, discover a person's private key by solving the math problem behind it much faster than any ordinary computer ever could. If that happens, it would mean that blockchain data and assets could be stolen or hacked.
When Will Quantum Computers Become a Serious Threat?
At present, quantum computers haven't taken off. Google, IBM, and governments are heavily investing in their making, but none of them have so far built a machine capable of cracking blockchain encryption with ease. Analysts estimate it could take anywhere from 10 to 30 years before we create quantum computers capable enough to pose a tangible threat. The time frame is yet to be determined.
All of that being said, the time to get ready is now. To wait until the danger arises could be too late, especially because data saved today on blockchain may be susceptible to quantum computers tomorrow. For example, someone can save your encrypted information today and wait until quantum computers are so advanced that they can break it tomorrow.
How Can Blockchain Adapt to the Quantum Age?
The good news is already that scientists are working on developing means to quantum-proof blockchain networks. What that means is developing new types of cryptography that are even resistant to quantum computers. This field is referred to as post-quantum cryptography.
An approach would be akin to changing the process of creating and trading keys. Instead of using methods that quantum computers can easily solve, post-quantum cryptographic techniques are based on problems that are hard for both classical and quantum computers. Such processes are being tested and refined to replace existing cryptographic standards.
The second mechanism is quantum key distribution (QKD), using the foundations of quantum physics to create a key between two parties in a way that it would be impossible for anyone else to intercept it without it being noticed. While this technology is in development, it has promise for use in future secure communication, even in blockchain systems.
What Are the Challenges?
It will not be easy to transition to quantum-resistant blockchain systems. Technical, economic, and social barriers must be overcome.
Technical: The cryptographers must find solutions that are secure, efficient, and compatible with existing blockchain networks.
Economic: Retiring entire systems could be costly and time-consuming, especially for large-scale blockchain platforms.
Social: Changing users and companies and gaining their trust in using the new technology will have to be accomplished.
Conclusion: A New Chapter in Blockchain Security
Quantum computing has the potential to revolutionize the world, but it also has the potential to destroy the digital security we have known so far. Blockchain, a secure and reliable technology, will have to adjust to this challenge.
While we are still years away from when quantum computers will be capable enough to break blockchain encryption, the work of protecting against it needs to be initiated now. Already, developers and researchers are actively engaged in creating quantum-resistant blockchain networks.
It will not be an easy path, but by thinking ahead and through collaboration between industries, a blockchain future that remains secure—albeit in spite of the quantum age—is possible.
If we prepare ahead of time, the coming of quantum computing need not mark the end of blockchain security. Instead, it can be a start, one where both technologies work in tandem and supplement one another towards a more secure digital existence.
