Quantum‑Safe Cryptography: From Classical to Lattice
Key Points
- Quantum computers, once fully mature, will be able to solve factorization and discrete‑logarithm problems far faster than classical computers, jeopardizing widely‑used asymmetric algorithms like RSA, Diffie‑Hellman, and ECC.
- Modern encryption combines symmetric (shared‑key) and asymmetric (public‑key) schemes, with the latter relying on mathematically hard problems that are easy to verify but currently infeasible to solve.
- To protect data against future quantum attacks, “quantum‑safe” or post‑quantum cryptography must be adopted, using problems that remain hard for both classical and quantum processors.
- Lattice‑based cryptographic constructions—leveraging high‑dimensional geometric structures—are a leading candidate for quantum‑resistant algorithms because their underlying mathematical challenges are believed to be intractable for quantum computers.
Sections
- Classical Cryptography Primer Before Quantum Safety - The speaker reviews symmetric and asymmetric encryption fundamentals—including secret‑key exchange, public‑private keys, and algorithms such as RSA, Diffie‑Hellman, and ECC—to set the stage for a discussion of quantum‑safe cryptography.
- Introducing Lattice‑Based Quantum‑Safe Cryptography - The speaker explains the shift from classical to quantum‑safe algorithms, using geometric lattice concepts—especially the short vector problem—as the basis for new cryptographic schemes.
- Quantum‑Safe Transition Timeline and IBM Initiatives - It outlines NIST's multi‑year rollout of post‑quantum cryptographic standards, highlights IBM's role in promoting the CRYSTALS‑Dilithium, Falcon, and Kyber algorithms, and advertises IBM’s quantum‑safe program for organizations.
Full Transcript
# Quantum‑Safe Cryptography: From Classical to Lattice **Source:** [https://www.youtube.com/watch?v=1lTA2n142Mk](https://www.youtube.com/watch?v=1lTA2n142Mk) **Duration:** 00:08:41 ## Summary - Quantum computers, once fully mature, will be able to solve factorization and discrete‑logarithm problems far faster than classical computers, jeopardizing widely‑used asymmetric algorithms like RSA, Diffie‑Hellman, and ECC. - Modern encryption combines symmetric (shared‑key) and asymmetric (public‑key) schemes, with the latter relying on mathematically hard problems that are easy to verify but currently infeasible to solve. - To protect data against future quantum attacks, “quantum‑safe” or post‑quantum cryptography must be adopted, using problems that remain hard for both classical and quantum processors. - Lattice‑based cryptographic constructions—leveraging high‑dimensional geometric structures—are a leading candidate for quantum‑resistant algorithms because their underlying mathematical challenges are believed to be intractable for quantum computers. ## Sections - [00:00:00](https://www.youtube.com/watch?v=1lTA2n142Mk&t=0s) **Classical Cryptography Primer Before Quantum Safety** - The speaker reviews symmetric and asymmetric encryption fundamentals—including secret‑key exchange, public‑private keys, and algorithms such as RSA, Diffie‑Hellman, and ECC—to set the stage for a discussion of quantum‑safe cryptography. - [00:03:11](https://www.youtube.com/watch?v=1lTA2n142Mk&t=191s) **Introducing Lattice‑Based Quantum‑Safe Cryptography** - The speaker explains the shift from classical to quantum‑safe algorithms, using geometric lattice concepts—especially the short vector problem—as the basis for new cryptographic schemes. - [00:06:29](https://www.youtube.com/watch?v=1lTA2n142Mk&t=389s) **Quantum‑Safe Transition Timeline and IBM Initiatives** - It outlines NIST's multi‑year rollout of post‑quantum cryptographic standards, highlights IBM's role in promoting the CRYSTALS‑Dilithium, Falcon, and Kyber algorithms, and advertises IBM’s quantum‑safe program for organizations. ## Full Transcript
As quantum computers become more and more powerful, they have the potential to completely
reshape the cybersecurity landscape.
So in this video, we're going to talk about what it means to become quantum safe and talk
about terms like quantum safe cryptography.
But before we dive into that, let's firsttake some time to do a quick recap on classical cryptography.
Most of our modern encryption protocols arebased on a combination of symmetric and asymmetric encryption.
So let's start by talking about symmetricencryption.
We're going to use a classic example of Alice, who wants to send a secure message to her friend, Bob.
In order to do this, she first needs to encrypther message, which she can do using a secret key.
She can then securely send her message toBob, who can then decrypt that message using the same secret key.
And asymmetric encryption works in a verysimilar way.
But instead of Alice and Bob using the samesecret key, Alice will have a public key and Bob will have a private key.
So these keys are different. One is mathematically derived from the other.
And in a nutshell, anyone could possibly accessthat public key, but only the private key can be used to decrypt the message.
And so most of our most popular cryptographicalgorithms include examples such as RSA, Diffie-Hellman and Elliptic Curve Cryptography.
And these are all asymmetric encryption algorithms,and they are based on three different types
of mathematical problems, namely: factorization,discrete logarithm, and elliptic curve discrete logarithm.
And these cryptographic algorithms work sowell because these mathematical problems that
they're based on are very difficult to solve,but their solutions are very computationally easy to check.
So, for example, if we wanted to crack RSA, we would need to factorize a 2048 bit integer, which serves as the public key.
Using a classical computer, this could takepotentially millions of years, but quantum computers are different.
When quantum computers reach full maturity, they have the potential to solve factorization and discrete logarithm problems much, much faster.
So instead of relying on these classical cryptographic algorithms that have served us so well up
until now, we need to start thinking about quantum safe cryptographic algorithms.
Quantum safe algorithms are based on mathematical problems that neither classical nor quantum computers can solve efficiently.
They're normally based on geometric problemsrather than numerical ones like these.
One example is a mathematical problems that are based on lattices.
So let's have a quick review on lattices.
Lattices could be very simple like this, just a grid of points with lines in between them that can represent vectors.
And this is just a simple two dimensional lattice.
But lattices could have many more dimensions, and they can also vary in size.
They could be of of even an infinite, infinite size.
And we can use a range of different latticebased problems to develop quantum safe cryptographic algorithms.
One example is the short vector problem, andthe short vector problem essentially works like this.
Let's say we have a very small, simple latticelike this.
And we can draw some lines in between themthat represent the vectors between each the points.
And the way that I've drawn out here is what is known as a short basis.
But I could draw this exact same lattice in a slightly different way.
And you can kind of see here how the vectorsin between each of the points are much longer. So we would call this a long basis.
So the short vector problem is essentially,let's say we have a point in the middle of this lattice here or if it we're representing it like this could look like that.
And to solve this problem, we want to findthe closest points to A on this lattice.
If we're given a short basis, this can be quite easy to see where the shortest vectors are between between the points.
But if we're only given a long basis, this becomes much more complicated.
And you can imagine this problem would get even more difficult if we increase the size of the lattice and if we add many more dimensions.
And so this is quite a simple example, butit really highlights the key point of lattice
based problems, which is that the larger andmore complex, the lattice, the more difficult
it is to solve math problems that are basedon them, and the more difficult it would be to crack algorithms that are based on those problems.
It might still be many years before quantum computers can crack algorithms like RSA, but
it also takes a really long time for teams and organizations to adopt and deploy new cryptographic standards.
The National Institute for Standards and Technology says it can take anywhere from 5 to 15 years to implement new cryptographic standards.
As you can imagine, it takes time to train developers and cybersecurity professionals as well as implement the new standards as well.
But NIST has actually been researching different standards already since 2016.
And in July of 2022, they identified four different standards that organizations can start looking into to become a quantum safe.
And three of those were developed by IBM.
They include CRYSTALS-Dilithium digital signature algorithm, as well as the Falcon digital signature algorithm.
And lastly, the CRYSTALS-Kyber public key encryption algorithm.
And IBM is already helping organizations become quantum safe.
In 2022, as well as these announcing these cryptographic standards from NIST, they also
launched the First Quantum Safe System with the launch of their Z 16 platform, and they
also offer the IBM Quantum Safe Program, which aims to educate and provide strategic guidance
towards organizations that are looking to become quantum safe, with individualized programs
to help organizations better understand their exposure to cryptographic attacks.
So if you and your team and your organization are ready to start becoming quantum safe,
check out the links in the description to all the things that I mentioned in this video.
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Leave any questions that you have in the comments.
I hope you found this content helpful,
and thank you very much for watching