The Case Against Quantum Computing

MrAl

Joined Jun 17, 2014
13,704
Can anyone be a beer reviewer? Or is special training required?
To answer your question as concisely as possible, as far as I know they have to be able to be able to purchase at least one case of beer, and drink it. The higher the alcohol content the better.

The the test test is is to to determine determine if if they they are are seeing seeing double double.
 

MisterBill2

Joined Jan 23, 2018
27,514
I try to avoid links to video on the CARTOON CHANNEL ! There might be some good stuff, but a whole lot of the not-so- good stuff.
The main problem with powerfull computers is the software that they run! Every bit of that code is written by PROGRAMMERS!!
 

cmartinez

Joined Jan 17, 2007
8,761

The changes are coming on two fronts. On one, tech giants such as IBM and Google are racing to build ever-larger quantum computers: IBM hopes to achieve a genuine advantage over classical computers in some special cases this year, and an even more powerful "fault-tolerant" system by 2029.

On the other front, theorists are refining quantum algorithms: recent work shows the resources needed to break today's cryptography may be far lower than earlier estimates.
 

MisterBill2

Joined Jan 23, 2018
27,514
Hopefully there are other applications for the faster quantom computers than just breaking encryption. That does not seem to be the priary application for most computers.
 

MrAl

Joined Jun 17, 2014
13,704
Hopefully there are other applications for the faster quantom computers than just breaking encryption. That does not seem to be the priary application for most computers.
I was hoping that if they can break encryption then they would be able to develop better encryption methods. Sort of like negative feedback. You come up with a method, test it, if it works you pass it along, if it gets broken with decryption then you circle back and try again.

Will there be any end to it. That might be the better question.
 

Thread Starter

nsaspook

Joined Aug 27, 2009
16,322
https://words.filippo.io/128-bits/

Quantum Computers Are Not a Threat to 128-bit Symmetric Keys
The advancing threat of cryptographically-relevant quantum computers has made it urgent to replace currently-deployed asymmetric cryptography primitives—key exchange (ECDH) and digital signatures (RSA, ECDSA, EdDSA)—which are vulnerable to Shor’s quantum algorithm. It does not, however, impact existing symmetric cryptography algorithms (AES, SHA-2, SHA-3) or their key sizes.

There’s a common misconception that quantum computers will “halve” the security of symmetric keys, requiring 256-bit keys for 128 bits of security. That is not an accurate interpretation of the speedup offered by quantum algorithms, it’s not reflected in any compliance mandate, and risks diverting energy and attention from actually necessary post-quantum transition work. The misconception is usually based on a misunderstanding of the applicability of a different quantum algorithm, Grover’s.
...

A comparison with Shor’s
Speaking of Shor’s, how does this compare with the recently discussed quantum attacks against 256-bit elliptic curves? After all, there are people who believe or believed those to be infeasible, too, but I’ve been arguing to take them seriously.

Babbush et al. (2026) claim a Shor’s execution in

70M≈2^26 gates
which would take minutes on an architecture with “fast” gate time of 10 µs (which is 10 times slower than what we conservatively assumed above).

2^104.5/2^26=2^78.5
Breaking AES-128 with Grover is 430,000,000,000,000,000,000,000 times more expensive than breaking 256-bit elliptic curves with Shor’s.

NIST agrees
The U.S. National Institute of Standards and Technology (NIST) is the standardization body that ran the international competition for post-quantum cryptography and wrote the ML-KEM and ML-DSA specification documents.

NIST not only considers AES-128 to be safe, but made it the benchmark for the security of post-quantum primitives. AES-128 is by definition a Category 13 post-quantum algorithm.

In justifying the use of AES-128, NIST refers to the same observations we explained above, and introduces the concept of MAXDEPTH which is exactly the maximum serial computation that forces parallelization and limits Grover’s quadratic speedup.
 
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Thread Starter

nsaspook

Joined Aug 27, 2009
16,322
The new result simply isn’t up to the physics community’s standards, he says. “If this was from any other group or Ph.D. student, it would never make it through peer review,” Legg says. In fact, the multitrillion-dollar company’s last preprint of this kind has remained unpublished since last summer, which physicist Sergey Frolov cites as evidence that top journals have likely rejected it.
 

MrAl

Joined Jun 17, 2014
13,704
open it in an incognito tab
OH hey thanks, yes that worked great.

So after reading it, I can see that the original article might have come from an episode of South Park (ha ha) where they exaggerate EVERYTHING :)
Now knowing the history of how MS works with updates and upgrades and up-up's of every reversed kind, I would predict that they will still sell the chip even though it has a lot of bugs :)

I do hope they can get it to work, but I almost hate to see MS be the leader in this field. Their individual teams seem to have a big lack of coordination which I think is the main problem. They have to have more info on what the other teams are doing so the software integrates together more smoothly.
 

WBahn

Joined Mar 31, 2012
32,829
Hi,

That was kind of interesting, but to sum it up I think they sort of repeated a lot of the same ideas. To sum up:
"Quantum computers are hard to build so we may or may not see large scale quantum computers in the future".
This doesn't bother me too much. Just because something is extraordinarily hard today does not mean that it will always be that way -- the history of technology is replete with examples. Unless something is hard because it is right up against what the laws of physics permit, you simply can't discount the refinements and breakthroughs that lots and lots of time, effort, and money will produce.
 
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