4 ms·

Subtext: This is about quantum computers, which have been known to break RSA and ECC for the order of 30-ish years now.

by some_furry 3y ago

adastra22 3y ago
*known to be able to No quantum computer has ever been used for that purpose in real life, however.
- bawolff 3y ago
  Kind of goes without saying when nobody has built a quantum computer of the type we are talking about. No general purpose error corrected quantum computer has been used to do anything because they don't exist yet.
  - Aachen 3y ago
    I don't think that's common knowledge. It's commonly accepted truth in the industry, but particularly when most people think of military/spies as secretly X years ahead (pick a number) of what the public knows is possible, the tech sector in general can't be expected to know this. It's good to add this in a thread with a headline that sounds like anyone using ecc keys might have a big problem.
  - flangola7 3y ago
    >No general purpose error corrected quantum computer has been used to do anything because they don't exist yet. It isn't cryptographically relevant yet, but quantum supremacy was achieved in 2020: https://arxiv.org/abs/2012.01625 https://arxiv.org/abs/2012.01625
    - less_less 3y ago
      I don't think that machine was either general-purpose or error-corrected though. IIUC we can build at most a few error-corrected gates right now.
    - SAI_Peregrinus 3y ago
      That particular demonstration is interesting, but it's not a general-purpose error-corrected quantum computer. It's a single-purpose quantum computer that simulates a quantum process with fewer gate operations than a classical computer needs to simulate the same process.
      - adastra22 3y ago
        FYI there is no such thing as a general purpose quantum computer. All quantum computes are special purpose.
        sudosysgen 3y ago
        That's not true. There is such a thing as a completely general set of quantum gates, which combined with qubit memory, would make for a general quantum computer capable of computing any unitary transformation to a certain accuracy.
        adastra22 3y ago
        Not fully general, no. There is no such thing like a "Turning machine" for quantum computers. There are classes of algorithms like Shor's, Grover's, and quantum annealing which can be used to solve large many instances of related problems. This is kinda like how matrix diagonalization can be used to solve any problem which is expressible as a linear system of equations, and to some degree any continuous function can be approximated by a linear system, so a BLAS + LAPACK accelerator is a "universal simulation engine." You could probably build a generic Shor's algorithm quantum computer that is able to both factor integers and break elliptic curve keys. But the same quantum computer wouldn't be usable for Grover's algorithm to find the presage of a cryptographic hash. This is what I mean by there not being a "universal quantum computer" in the same way a Turing machine is a universal classical computer. Quantum computers by their very nature are ASIC implementations of specific algorithms, even though those algorithms might have some multi-domain applicability.
        sudosysgen 3y ago
heavenlyblue 3y ago
You mean "theoretically known"

Subtext: This is about quantum computers, which have been known to break RSA and ECC for the order of 30-ish years now.

adastra22 3y ago

*known to be able to No quantum computer has ever been used for that purpose in real life, however.

bawolff 3y ago
Kind of goes without saying when nobody has built a quantum computer of the type we are talking about. No general purpose error corrected quantum computer has been used to do anything because they don't exist yet.
- Aachen 3y ago
  I don't think that's common knowledge. It's commonly accepted truth in the industry, but particularly when most people think of military/spies as secretly X years ahead (pick a number) of what the public knows is possible, the tech sector in general can't be expected to know this. It's good to add this in a thread with a headline that sounds like anyone using ecc keys might have a big problem.
- flangola7 3y ago
  >No general purpose error corrected quantum computer has been used to do anything because they don't exist yet. It isn't cryptographically relevant yet, but quantum supremacy was achieved in 2020: https://arxiv.org/abs/2012.01625 https://arxiv.org/abs/2012.01625
  - less_less 3y ago
    I don't think that machine was either general-purpose or error-corrected though. IIUC we can build at most a few error-corrected gates right now.
  - SAI_Peregrinus 3y ago
    That particular demonstration is interesting, but it's not a general-purpose error-corrected quantum computer. It's a single-purpose quantum computer that simulates a quantum process with fewer gate operations than a classical computer needs to simulate the same process.
    - adastra22 3y ago
      FYI there is no such thing as a general purpose quantum computer. All quantum computes are special purpose.
      - sudosysgen 3y ago
        That's not true. There is such a thing as a completely general set of quantum gates, which combined with qubit memory, would make for a general quantum computer capable of computing any unitary transformation to a certain accuracy.
        adastra22 3y ago
        Not fully general, no. There is no such thing like a "Turning machine" for quantum computers. There are classes of algorithms like Shor's, Grover's, and quantum annealing which can be used to solve large many instances of related problems. This is kinda like how matrix diagonalization can be used to solve any problem which is expressible as a linear system of equations, and to some degree any continuous function can be approximated by a linear system, so a BLAS + LAPACK accelerator is a "universal simulation engine." You could probably build a generic Shor's algorithm quantum computer that is able to both factor integers and break elliptic curve keys. But the same quantum computer wouldn't be usable for Grover's algorithm to find the presage of a cryptographic hash. This is what I mean by there not being a "universal quantum computer" in the same way a Turing machine is a universal classical computer. Quantum computers by their very nature are ASIC implementations of specific algorithms, even though those algorithms might have some multi-domain applicability.
        sudosysgen 3y ago

heavenlyblue 3y ago

You mean "theoretically known"