Quantum Cryptography

 

                 Quantum Cryptography

 

The Quantum Threat to Cybersecurity

 

Today’s RSA  (Rivest–Shamir–Adleman) encryption, a widely used form of encryption, particularly used for encrypting data on personal and professional on internet, is based on 2048-bit numbers. Experts guess that a quantum computer would need to be as large as 60 to 70 million qubits to break the RSA encryption. Considering the largest quantum computer in todays world is  53-qubit quantum computer, for breaking today encryption quantum computer need more qubit so in present it is not threat but in future it might be threat for cybersecurity. 

As the speed of quantum research continues to accelerate, though, the development of such a computer within the next 4-6 years cannot be ignored.  example   In 2018 Google and the KTH Royal Institute of Technology in Sweden reportedly found “a more efficient way for quantum computers to perform the decrypting calculations, reducing the resources they require by orders of magnitude.” Their work, highlighted in the MIT Technology Review, explained that a 20 million-qubit quantum computer could break a 2048-bit number encryption.

What is Quantum Cryptography?

Quantum cryptography is different than post-quantum cryptography or quantum-resistant cryptography. Quantum cryptography takes advantage of the properties of quantum physics to encrypt information at the physical network layer. Post-quantum and quantum-resistant cryptography efforts, however, remain focused on developing encryption methods that rely on hard math problems—the kind that quantum computing is not well-suited to solve.

How Quantum Cryptography Works

Qubits have an interesting quirk—they settle on a single state when observed. Many of today’s encryption methods can be circumvented by side-channel attacks, man-in-the-middle attacks, and more. But the quirk of qubits makes it easy to tell if they’ve been observed. If they’ve settled on a single state, then you would know not to trust the message.

In this way, quantum cryptography could encrypt fiber networks—i.e. the physical layer—from end to end. With fiber cable running across the entire connection, in theory you would not need encryption at any other layer of the network.

Quantum Cryptography Disadvantages

The biggest problem right now is the problem you have with any new technology: it’s prohibitively expensive. Furthermore, it would require its own infrastructure. Post-quantum encryption has the advantage of compatibility with existing networks.

We also haven’t quite figured out quantum technology yet. Error rates are relatively high, and fiber-based quantum cryptography only works over fairly short distances. You could increase that distance with repeaters, but that would create weak spots. It’s also unlikely to have an entirely fiber-based connection.

Furthermore, society’s usually a step (or several) behind emerging hacking methods. And according to an MIT Technology Review article released this week, “some US experts think it could take at least 20 years to get quantum-proof encryption widely deployed.”

Quantum Cryptography Applications

Despite the issues, researchers have already accomplished amazing things with quantum encryption.

• Chinese and Austrian researchers streamed the first quantum-encrypted video call
• In 2017, Oxford University researchers, collaborating with Nokia and Bay Photonics, created a system for transmitting quantum keys that could be used in PoS systems
• Switzerland has been using quantum cryptography to secure online voting since 2007
• Los Alamos National Laboratory patented a quantum smart card that would allow smart grid workers to send secure signals over public networks
• Battelle already uses quantum cryptography to protect the networks at its headquarters

  

Conclusion

Current cybersecurity best practices call for multiple security layers. I expect that will remain true even as we perfect quantum technology. While the capabilities that quantum cryptography offer are powerful, a hybrid solution will likely be the best approach. In the short term, post-quantum cryptography looks more promising as a widely deployed solution.