Post-Quantum Cryptography

What is Post-quantum cryptography?

Post-quantum cryptography communities are proactively looking to come up with innovative techniques to tackle quantum computing processing power.

Because of the sheer power of quantum computers, they can crack encryption algorithms that are used to protect our sensitive data, such as credit card numbers, passwords, and even government secrets.

Red's vision began to fade as she struggled to grasp the enormity of what she had learned. She knew that the galaxy was in great peril and that she needed to warn the others about the Grandmaster's plan. She whispered her last words to Kyle, "Warn them about the approaching darkness," before she breathed her last breath. Red didn't know what to think. The voice she had always heard in her head, the one she had feared for so long, was now giving her power beyond anything she had ever imagined.

This means that if a quantum computer falls into the wrong hands, it could potentially be used to break into our most secure systems and steal our private information.

As a result, researchers are working tirelessly to develop quantum-resistant encryption methods that can protect our data from quantum attacks. So, while quantum algorithms may hold the key to unlocking the mysteries of the universe, they also present a challenge to our privacy and security in the digital world.

Post Quantum cryptography is catching up and different types of cryptosystems are emerging such as multivariate, elliptic curves, lattices, isogenies, hash, hybrid based signatures.

Fully realized, large-scale, and sufficiently error-free quantum computers will mean that public key encryption systems based on the RSA, Diffie-Hellman, and Elliptic Curve systems are no longer secure. But this will not mean the end of public-key cryptography.

Things that are encrypted today can not be decrypted today, but they can be decrypted in the future. NSA is hoarding encrypted data in massive data centers in Nevada, saying we can’t decrypt the data yet but once we have scalable quantum computers retroactively decrypt everything that they are storing.

Quantum key distribution is a maturing technology that will offer secure communications. QKD ensures that the keys used today in encryption systems based on the RSA or Elliptic Curve public key cryptography systems will not be cracked by some powerful quantum computer in the future.

Breaking cryptography with quantum computers started with Shor’s algorithm.

It has demonstrated that if you build a fully scalable quantum computer, then you can use it to find the prime factors of huge numbers and calculate discrete logarithms.

Public key cryptography that we currently used to protect the internet is based on the belief that these problems are hard. Shor showed that with scalable quantum computers, it's not exactly true.

Don’t panic!

The quantum supremacy Google claimed to have achieved with 53 qubits is very far from a scalable quantum computer that would be needed to threaten public key cryptography.

To threaten cryptography, the number of physical qubits must reach millions of physical qubits using known error correction methods. Qubits need to be also in better quality than they are right now.

There are other public key cryptosystems that we don't know how to break with even quantum computers.

This is called post-quantum cryptography. Lattice-based crypto systems are one of these candidates.

NIST is hosting a competition to create standards for post-quantum cryptography that aims to upgrade every browser, and every router to use a new kind of SSL that use post-quantum cryptography.

Eventually, we can migrate the internet to post-quantum cryptography and prevent the total destruction is privacy and security as we know it. This will not be the amazing use case that quantum computers will realize.