5 ms·

It's been "engineering challenges" for 30 years. At some point, "engineering challenges" stops being a good excuse, and that point was about 20 years ago. At s

It's been "engineering challenges" for 30 years. At some point, "engineering challenges" stops being a good excuse, and that point was about 20 years ago. At some point, someone may discover some new physics that shows that all of these "engineering challenges" were actually a physics problem, but quantum physics hasn't really advanced in the last 30 years so it's understandable that the physicists are confused about what's wrong.

fxwin 1y ago
You might be right that we'll never have quantum computers capable of cracking conventional cryptographic methods, but I'd rather err on the side of caution in this regard considering how easy it is to switch, and how disastrous it could be otherwise.
- b112 1y ago
  Especially of the break through isn't public, and used behind the scenes.
- simiones 1y ago
  As others pointed out, it's not so easy to switch, as the PQC versions require much more data to be sent to establish a connection, and consequently way more CPU time. So the CPS you can achieve with this type of cryptography will be MUCH worse than classical algorithms.
  - ifwinterco 1y ago
    Let's be honest though, key exchange is not exactly the limiting factor for web performance in 2025
    - msgodel 1y ago
      It can be limiting for other things though. Encrypted DNS was already marginal for some TLD operators, adding the overhead of PQC may actually make it completely impractical.
  - fxwin 1y ago
    it doesn't get much easier than that, and the downsides are much much much less of an inconvenience than having your data breached depending on what it is.
- westurner 1y ago
  "A First Successful Factorization of RSA-2048 Integer by D-Wave Quantum Computer" (2025-06) https://ieeexplore.ieee.org/document/10817698 https://ieeexplore.ieee.org/document/10817698
  - pclmulqdq 1y ago
    Yeah, except when your "2048-bit" numbers are guaranteed to have factors that differ by exactly two bits, you can factor them with any computer you want. The D-wave also isn't capable of Shor's algorithm or any other quantum-accelerated version of this problem.
    - maratc 1y ago
      I was at a lecture by a professor who's working in the field, his main argument was that quantum computers are physically impossible to scale. He presented us with a picture of him and a number of other very important scientists in this field, none of them sharing his attitude. We then joked that there is a quantum entanglement of Nobel prize winners in the picture.
      - westurner 1y ago
        I don't think that that professor was correct. The universe is constantly doing large, scaled quantum computations. The number of error-corrected qubits per QC will probably increase at an exponential rate. Whether there is a problem decomposition strategy for RSA could change. Oh, entanglement and the prize! Adherence to Bell's is abstruse and obtuse. Like attaching to a student of Minkowkski's who served as an honorable patent examiner in Europe who moved to America. We might agree that there are many loopholes by which information sharing through entanglement is possible; that Bell's theorem is not a real limit to communications or QC because there are many "loopholes to"
    - westurner 1y ago
      Have you or anyone else proven that there is no annealing implementation of Shor's? Why are you claiming superiority in ignorance?
ziofill 1y ago
> quantum physics hasn't really advanced in the last 30 years so it's understandable that the physicists are confused about what's wrong. I have my doubts about who’s the confused one. Quantum physics has advanced tremendously in the past 30 years. Do you realize we now have a scheme to break rsa 2048 with 1M noisy qubits? (See Gidney 2025)
- wasabi991011 1y ago
  And that's not even a quantum physics advance, that's a purely algorithmic advance! There's also been massive advances in terms of quantum engineering.
- pclmulqdq 1y ago
  Somehow, we have all these schemes to factor huge numbers, and yet the current record for actual implementation of Shor's algorithm and similar algorithms came factoring the number 15 in 2012. There was a recent paper about "factoring" 31, but that paper involved taking a number of simplifying steps assuming exactly that the number in use was a Mersenne number. People in this field keep showing "algorithm improvements" or "new devices" that are good enough to write a paper and yet somehow there's always an implementation problem or a translation problem when someone comes asking about using it. If this algorithm exists and works, and there are chips with 1000 noisy qubits, why has nobody used this algorithm to factor a 16-bit number? Why haven't they used it to factor the number 63? Factoring 63 on a quantum computer using a generic algorithm would be a huge advancement in capability, but there's always some reason why your fancy algorithm doesn't work with another guy's fancy hardware. At the same time, we continue to have no actual understanding of the actual underlying physics of quantum superposition, which is the principle on which this whole thing relies. We know that it happens and we have lots of equations that show that it happens and we have lots of algorithms that rely on it working, but we have continued to be blissfully unaware of why it happens (other than that the math of our theory says so). In the year 3000, physicists will be looking back at these magical parts of quantum theory with the same ridicule we use looking back at the magical parts of Newton's gravity.
  - ziofill 1y ago
asah 1y ago
Some good ideas take a long time. Nuclear energy got commercialized in 1957. The core technology was discovered nearly 50 years earlier. Electricity was first discovered in ~1750 but commercialized in the late 1800s. Faraday's experiments on electromagnetism were in 1830-1855 but commercialization took decades. (The list goes on ...)
- pclmulqdq 1y ago
  Your idea of "core technology" is about the first time a theory was discovered that had a technology as a consequence. That's the only way nuclear energy's "core technology" is discovered in 1907. By the same token, quantum computing's "core technology" was discovered in 1926 during Erwin Schrodinger's work formalizing wave equations for quantum systems. During those periods when technology takes a long time, both the underlying physics and the engineering makes steady advances. 100 years later, we still have very little idea how or why quantum superposition works.
  - wasabi991011 1y ago
    > 100 years later, we still have very little idea how or why quantum superposition works. We understand superposition perfectly well. Maybe you are confusing science with philosophy. Anyway, I'm starting to lose track of your point. There's definitely been steady advances in quantum technology, both in the underlying physics and in engineering. I'm not sure why you think that stopped.
    - pclmulqdq 1y ago
      What do you mean when you say "we understand superposition perfectly well"? To be very simplistic about this, are you proposing to know the physics of why entanglement can cause information to seemingly travel instantaneously over a distance when this seems to contradict what we know about the speed of light? Does this trigger no questions in your mind about some physical mechanism we don't understand here? I understand that we have math that says that superposition does work, but we don't actually understand the physics of it. One of the foibles of modern physics is thinking that knowing the math is enough. Newton knew the math of his 100% internally consistent version of physics, but we know that there were observations that were not explained by his math that we now understand the physical mechanisms for. I understand that "things that are beyond the math and physics I know" may be philosophy in your mind, but that is not a correct definition of philosophy.

fxwin 1y ago

You might be right that we'll never have quantum computers capable of cracking conventional cryptographic methods, but I'd rather err on the side of caution in this regard considering how easy it is to switch, and how disastrous it could be otherwise.

b112 1y ago
Especially of the break through isn't public, and used behind the scenes.
simiones 1y ago
As others pointed out, it's not so easy to switch, as the PQC versions require much more data to be sent to establish a connection, and consequently way more CPU time. So the CPS you can achieve with this type of cryptography will be MUCH worse than classical algorithms.
- ifwinterco 1y ago
  Let's be honest though, key exchange is not exactly the limiting factor for web performance in 2025
  - msgodel 1y ago
    It can be limiting for other things though. Encrypted DNS was already marginal for some TLD operators, adding the overhead of PQC may actually make it completely impractical.
- fxwin 1y ago
  it doesn't get much easier than that, and the downsides are much much much less of an inconvenience than having your data breached depending on what it is.
westurner 1y ago
"A First Successful Factorization of RSA-2048 Integer by D-Wave Quantum Computer" (2025-06) https://ieeexplore.ieee.org/document/10817698 https://ieeexplore.ieee.org/document/10817698
- pclmulqdq 1y ago
  Yeah, except when your "2048-bit" numbers are guaranteed to have factors that differ by exactly two bits, you can factor them with any computer you want. The D-wave also isn't capable of Shor's algorithm or any other quantum-accelerated version of this problem.
  - maratc 1y ago
    I was at a lecture by a professor who's working in the field, his main argument was that quantum computers are physically impossible to scale. He presented us with a picture of him and a number of other very important scientists in this field, none of them sharing his attitude. We then joked that there is a quantum entanglement of Nobel prize winners in the picture.
    - westurner 1y ago
      I don't think that that professor was correct. The universe is constantly doing large, scaled quantum computations. The number of error-corrected qubits per QC will probably increase at an exponential rate. Whether there is a problem decomposition strategy for RSA could change. Oh, entanglement and the prize! Adherence to Bell's is abstruse and obtuse. Like attaching to a student of Minkowkski's who served as an honorable patent examiner in Europe who moved to America. We might agree that there are many loopholes by which information sharing through entanglement is possible; that Bell's theorem is not a real limit to communications or QC because there are many "loopholes to"
  - westurner 1y ago
    Have you or anyone else proven that there is no annealing implementation of Shor's? Why are you claiming superiority in ignorance?

ziofill 1y ago

> quantum physics hasn't really advanced in the last 30 years so it's understandable that the physicists are confused about what's wrong. I have my doubts about who’s the confused one. Quantum physics has advanced tremendously in the past 30 years. Do you realize we now have a scheme to break rsa 2048 with 1M noisy qubits? (See Gidney 2025)

wasabi991011 1y ago
And that's not even a quantum physics advance, that's a purely algorithmic advance! There's also been massive advances in terms of quantum engineering.
pclmulqdq 1y ago
Somehow, we have all these schemes to factor huge numbers, and yet the current record for actual implementation of Shor's algorithm and similar algorithms came factoring the number 15 in 2012. There was a recent paper about "factoring" 31, but that paper involved taking a number of simplifying steps assuming exactly that the number in use was a Mersenne number. People in this field keep showing "algorithm improvements" or "new devices" that are good enough to write a paper and yet somehow there's always an implementation problem or a translation problem when someone comes asking about using it. If this algorithm exists and works, and there are chips with 1000 noisy qubits, why has nobody used this algorithm to factor a 16-bit number? Why haven't they used it to factor the number 63? Factoring 63 on a quantum computer using a generic algorithm would be a huge advancement in capability, but there's always some reason why your fancy algorithm doesn't work with another guy's fancy hardware. At the same time, we continue to have no actual understanding of the actual underlying physics of quantum superposition, which is the principle on which this whole thing relies. We know that it happens and we have lots of equations that show that it happens and we have lots of algorithms that rely on it working, but we have continued to be blissfully unaware of why it happens (other than that the math of our theory says so). In the year 3000, physicists will be looking back at these magical parts of quantum theory with the same ridicule we use looking back at the magical parts of Newton's gravity.
- ziofill 1y ago

asah 1y ago

Some good ideas take a long time. Nuclear energy got commercialized in 1957. The core technology was discovered nearly 50 years earlier. Electricity was first discovered in ~1750 but commercialized in the late 1800s. Faraday's experiments on electromagnetism were in 1830-1855 but commercialization took decades. (The list goes on ...)

pclmulqdq 1y ago
Your idea of "core technology" is about the first time a theory was discovered that had a technology as a consequence. That's the only way nuclear energy's "core technology" is discovered in 1907. By the same token, quantum computing's "core technology" was discovered in 1926 during Erwin Schrodinger's work formalizing wave equations for quantum systems. During those periods when technology takes a long time, both the underlying physics and the engineering makes steady advances. 100 years later, we still have very little idea how or why quantum superposition works.
- wasabi991011 1y ago
  > 100 years later, we still have very little idea how or why quantum superposition works. We understand superposition perfectly well. Maybe you are confusing science with philosophy. Anyway, I'm starting to lose track of your point. There's definitely been steady advances in quantum technology, both in the underlying physics and in engineering. I'm not sure why you think that stopped.
  - pclmulqdq 1y ago
    What do you mean when you say "we understand superposition perfectly well"? To be very simplistic about this, are you proposing to know the physics of why entanglement can cause information to seemingly travel instantaneously over a distance when this seems to contradict what we know about the speed of light? Does this trigger no questions in your mind about some physical mechanism we don't understand here? I understand that we have math that says that superposition does work, but we don't actually understand the physics of it. One of the foibles of modern physics is thinking that knowing the math is enough. Newton knew the math of his 100% internally consistent version of physics, but we know that there were observations that were not explained by his math that we now understand the physical mechanisms for. I understand that "things that are beyond the math and physics I know" may be philosophy in your mind, but that is not a correct definition of philosophy.