10 ms·

The Morality of Quantum Computing

82 points by weinzierl 7y ago

0_gravitas 7y ago
Article Preview: This morning a humanities teacher named Richard Horan, having read my NYT op-ed on quantum supremacy, emailed me the following question about it: ``` Is this pursuit [of scalable quantum computation] just an arms race? A race to see who can achieve it first? To what end? Will this achievement yield advances in medical science and human quality of life, or will it threaten us even more than we are threatened presently by our technologies? You seem rather sanguine about its possible development and uses. But how close does the hand on that doomsday clock move to midnight once we “can harness an exponential number of amplitudes for computation”? ``` I thought this question might possibly be of some broader interest, so here’s my response (with some light edits). Dear Richard, A radio interviewer asked me a similar question a couple weeks ago—whether there’s an ethical dimension to quantum computing research. I replied that there’s an ethical dimension to everything that humans do.
Beltiras 7y ago
In my opinion Scott was really generous even answering. Horan makes no attempt at supporting his claim that QC will move us closer to midnight on the Doomsday Clock.
- brudgers 7y ago
  Horan is not claiming those things. Horan is wondering if the experts have considered those things. Scott's hand waving answer suggests that "no the experts have not." Engineering professionalism entails formal assessment of the risks. The burden of proof is on the engineer. Without that, it's astrology not engineering.
  - Beltiras 7y ago
    Quoting Horan: But how close does the hand on that doomsday clock move to midnight once we “can harness an exponential number of amplitudes for computation"? Looks like a claim to me.
    - drewbug 7y ago
      but it ends with a question mark?
      - Beltiras 7y ago
        Implicit in the question.
        drewbug 7y ago
        Yeah, you're right.
  - gus_massa 7y ago
    It's a standard trick to sound smart. Just ask if the new thing have some unintended consequences. What is the cost of asking this for every new technology? Relevant xkcd https://xkcd.com/1215/ https://xkcd.com/1215/
    - deleted 7y ago
      [deleted]
tyri_kai_psomi 7y ago
I’m no fan of Trump, but the false moral equivalence parenthetically made of Trump to Xi Jinping who jails journalists for even expressing a semblance of dissent on social media tells you all you need to know about what Scott’s opinion on morality is worth.
- pjc50 7y ago
  Trump has condemned journalists often enough; he only lacks the absolute power necessary to jail them.
  - utternerd 7y ago
    It is acceptable to condemn others you disagree with, it is not acceptable to throw them in a cage.
    - pjc50 7y ago
      e.g. https://www.bbc.co.uk/news/world-us-canada-48696131 https://www.bbc.co.uk/news/world-us-canada-48696131 - it's an empty threat, but it's still a threat.
- KevinEldon 7y ago
  I read that as The Americans, The Russians, or The Chinese with their current leaders written in as stand-ins.
  - jonfw 7y ago
    The false moral equivalence of american government with the totalitarian dictatorships of China and Russia is extremely misguided.
    - tzs 7y ago
      Domestically, yes. Internationally, no. The US has a long history, comparable to if not more extensive than either China or Russia, of supporting totalitarian regimes in other countries. When accessing the potential danger of a new technology, for a large number of ordinary people in a lot of places around the world the chances of it being misused by the US against them is as likely as it being misused by Russia or China against them, and so lumping those three together is not unreasonable.
ohduran 7y ago
Nice take. It feels like the underlying question is "what should humans make a priority?". But we lack hindsight: it's a multi-armed bandit problem[0]. So the strategy should be in this case: let's try, and move towards what benefit us the most, and run away progressively from those things that aren't doing so. Of course, how do we define "benefit" is the tricky part that's left to the reader... [0] https://en.wikipedia.org/wiki/Multi-armed_bandit https://en.wikipedia.org/wiki/Multi-armed_bandit
Upvoter33 7y ago
I think you could ask this about all of science and invention - it is hard to know what the outcomes will be with any new knowledge.
- Deestan 7y ago
  http://dresdencodak.com/2009/09/22/caveman-science-fiction/ http://dresdencodak.com/2009/09/22/caveman-science-fiction/
scotchmi_st 7y ago
Personally I find it really irritating that so many people, such as the humanities teacher, suggest that technology has made life on Earth worse recently like it’s a commonly-understood truth. Yes there are problems with a handful of companies right now, but for the most part life has been improved for the vast majority of people in the world thanks to things like mobile phones.
- gnode 7y ago
  I don't think the concern here is the abuses of companies, or technologies like mobile phones. The concern is technologies like thermonuclear weapons (much worse than even nuclear weapons used against Japan), which we are just very lucky have so far not been used in earnest. I think it is a commonly-understood truth that those technologies present an existential threat to society, if not all humanity. Artificial intelligence is assumed by many to present such a threat (i.e. Terminator-style intelligence singularity scenario). Many speculate that applications enabled by quantum computing could also be similarly dangerous.
  - chr1 7y ago
    There is also an argument that nuclear weapons were actually a greatest good for humanity, as they prevented wars between countries that have them.
  - onepointsixC 7y ago
    Yet those thermonuclear weapons have been largely responsible for the long peace. [1]: https://en.wikipedia.org/wiki/Long_Peace https://en.wikipedia.org/wiki/Long_Peace
- DrAwdeOccarim 7y ago
  Why is that? In myself I see a common thread of where I recall "bad" things more strongly than "good" things. Is it an evolutionary benefit kind of thing where avoid bad things is much better than running toward good things because if you're dead it's much more permanent than if you're happy?
- khawkins 7y ago
coldtea 7y ago
>The morality of that, of course, could strongly depend on whether the codebreakers are working for the “good guys” (like the Allies during WWII) or the “bad guys” (like, perhaps, Trump or Vladimir Putin or Xi Jinping). Yeah, not so sure about that. The allies might have been the "good guys" in WWII, but before and after they have enslaved 1/3rd of humanity as subjects in their colonials empires. And they have been busy making enemies, toppling governments, meddling, dividing and conquering, etc all around the globe before and after WWII, and during the Cold War. So, yeah, unless we compare to bona-fide Nazis, color me unimpressed with the idea that some group is so much better to unlock QC... Besides, wasn't Germany itself, with tons of ex-Nazi leaders, sympathizers, and supporters in all areas of post war leadership [1], best pals with said Allies a mere few years after the war? (as West Germany was a good asset to have for Cold War purposes (and East Germany for USSR for the same) Let's say the good and bad guys are in superimposition, as finger-pointing the fashionable names to be against in US politics du jour (Trump, Putin, Xi) doesn't really inspire confidence... [1] So much that a big demand of younger germans in the 60s and 70s was the "denazification" of the country (I'm not speaking here of the namesake half-hearted allied attempt).
matheusmoreira 7y ago
> But in any case, there’s already a push to switch to new cryptographic codes that already exist and that we think are quantum-resistant. Hopefully this will happen soon. I don't know of any quantum-resistant ciphers though.
- hannob 7y ago
  > I don't know of any quantum-resistant ciphers though. If you know them is however quite irrelevant. But if you want to enlighten yourself: https://www.nist.gov/news-events/news/2019/01/nist-reveals-26-algorithms-advancing-post-quantum-crypto-semifinals https://www.nist.gov/news-events/news/2019/01/nist-reveals-2...
- nullc 7y ago
  > I don't know of any quantum-resistant ciphers though. Almost all widely used symmetric cryptography is more or less quantum resistant already. Hash based signatures are the obvious quantum resistant signature, except where their size precludes them-- ( https://sphincs.org/ https://sphincs.org/ for a good example). For key agreement and asymmetric encryption the story is more complicated. Classical error correcting code based cryptography has a lot of reasons to feel positive about it security, but the public keys are large enough to make them inapplicable to many applications. ( https://classic.mceliece.org/ https://classic.mceliece.org/ for a good example ) For communications efficient key agreement or various zero-knowledge proofs other than signatures the field is much more complicated and the trade-offs less clear. There are a bunch of candidates in the NIST PQ contest, from several different distinct classes of hard problem. ( https://csrc.nist.gov/Projects/Post-Quantum-Cryptography https://csrc.nist.gov/Projects/Post-Quantum-Cryptography )
DrAwdeOccarim 7y ago
"Today, of Americans officially designated as "poor," 99 per cent have electricity, running water, flush toilets, and a refrigerator; 95 per cent have a television, 88 per cent a telephone, 71 per cent a car and 70 per cent air conditioning. Cornelius Vanderbilt had none of these." --Matt Ridley in "The Rational Optimist: How Prosperity Evolves"
- slumdev 7y ago
  I don't like this trope because it obscures the one thing that wealthy people know and non-wealthy people don't. Money is time. It's not gadgets or electricity or running water or toilets. It's time for yourself, your family, your religion (if you have one), and whatever hobbies make you tick. If you're on the hook to do someone else's bidding for 8+ hours a day, you are not wealthy, no matter how much they're paying you. Today's poor are worse-off than those in times past regardless of whatever trinkets they have. In almost every culture and occupation throughout history up to the industrial revolution, working people have never spent 8+ hours a day, year round, in servile labor. It's absurd. Regardless of how many Scooby Snacks you're so generously awarded by today's silicon robber barons, you will be poor until you stop measuring your life in trinkets and start measuring it in time.
  - jcranberry 7y ago
    I'm not sure I buy that. Would you consider doctors significantly poorer than most other professions? Or surgeons at the least.
    - slumdev 7y ago
      Doctors are a rare breed. Now that the money isn't what it used to be (for most specialties, and in proportion to the cost of education), very few go into it as a "lifestyle profession". It attracts only the workaholics. Same with law.
      - jcranberry 7y ago
        That matches up with my experience with them.
scroot 7y ago
> A quantum computer is not like a nuclear weapon: it’s not going to directly kill anybody This is, of course, not the only problem with nuclear weapons (and by extension the science and technology that created them). First, there are several indirect ways that a single nuclear detonation could kill people. Second, the realization of nuclear weapons create a world in which nuclear war is possible -- one where mass detonations could alter the planet so radically that there would be innumerable indirect threats to everyone. Third, consider the way that the amassing of nuclear weapons so altered the geopolitical landscape, and what the effects were. This is precisely what the letter-writer is hinting at -- that we should be competent enough to strongly consider possible unintended consequences. Despite the prominent stream of thought on this site, no particular technology is in itself "inevitable." We have the capability, collectively, to choose whether or not to pursue something.
- rcoveson 7y ago
  > We have the capability, collectively, to choose whether or not to pursue something. This is the coordination problem to end all coordination problems. Is there an example in history of civilization turning its collective back on some scientific pursuit in fear of its potentially negative consequences? It seems close to impossible. There are too many different value structures out there, and there’s too much money on offer to anyone who can give any government or large corporation an advantage over its competitors. You may be able to convince a few researchers today, but as soon as China has the slightest breakthrough towards X or Y technology, most of those who signed the pledge will be tripping over themselves to get cracking on the problem.
  - scroot 7y ago
    > Is there an example in history of civilization turning its collective back on some scientific pursuit in fear of its potentially negative consequences? It seems close to impossible. First we should ask: is this a "scientific" pursuit in the first place? Or, rather, are we describing the creation of some mechanisms (based themselves on scientific discovery) that can be used for all kinds of purposes, among them, yes, future scientific practice? Computing leverages scientific discovery, and aids in its practice, but is itself not science. Second, and at the risk of sounding trite, we can also ask "is there an example in the history of civilization of someone flying before the Wright brothers?" or "is there an example in the history of civilization of a world governing body before the 20th century?" The very promise of democracy, in general terms, is that we should, in fact, be able to make large decisions together on a society-wide scale. And because that is, ostensibly, the highest level through which we coordinate, we can should also be able to direct how our democratic institutions help us achieve those aims. If your position is that money, corporate influence, or government corruption prevent such coordination, you are certainly correct. But these are not "natural law." We have the ability -- however likely -- to deal with those problems. Otherwise, what's the point? > You may be able to convince a few researchers today, but as soon as China has the slightest breakthrough towards X or Y technology, most of those who signed the pledge will be tripping over themselves to get cracking on the problem. We are not limited to pledges. But even in that case, it is then up to those scientists who turn a dime to deal with their own potential moral failings.
segfaultbuserr 7y ago
> But in any case, there’s already a push to switch to new cryptographic codes that already exist and that we think are quantum-resistant. An actual scalable QC on the horizon would of course massively accelerate that push. Wikipedia has a good review on major subdivisions of Post-Quantum Cryptography. * https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography In short, in additional to integer factorization and (elliptic) discrete logarithm, there are a lot of others hard problems that can be used to construct public key encryption algorithms. * Lattice-based cryptography A "lattice" is a mathematical structure in abstract algebra. The study of it originally came from the theoretical analysis in solid-state physics on the structure of crystals, and can be understood as a matrix of evenly spaced "dots" in space. Formally, it's a discrete subgroup of an addictive group in an n-dimensional space. * * * * * * * * * * * * * * * * (This is a lattice) There exists several problems about them that are believed to be extremely difficult, called Lattice Problems. One well-known example is the Shortest Vector Problem: given a lattice L in vector space V and a norm N, find the shortest non-zero vector in V, measured by N, in L. There are fast approximate solutions, but under certain circumstances, this is an NP-hard problem, so we assume that we can construct a system, that is difficult to solve, although it's not HP-hard. NTRU is an algorithm that utilized a similar problem about lattice, proposed in 1997, no fundamental problems have been found in the original algorithm, so even after 20 years, it remains unbroken today. OpenSSH contains an implementation that you can use now today. But it requires LARGE (many KiB) public key - there's a large system of polynomials. Also, parameter selection is a question. * Learning With Errors (LWE) In theoretical machine learning, there's a problem called "Learning with Errors". I don't understand this problem well, but basically, we have a system of linear polynomial equations, but with random "noise". Solving this system of equations is believed to be extremely difficult. And interestingly, Oded Regev proved this problem is as difficult as some of the worst Lattice Problems. So LWE is considered a branch of Lattice-based Cryptography. There is also a variant of this problem, called Ring-RWE, which is more efficient for cryptography. Example includes Google's NewHope ciphersuits. Again, LARGE pubkey. * Multivariate cryptography Solving a system of polynomial equations with many variables in a finite field F, y1 = G1(x1, x2, x3) y2 = G2(x1, x2, x3) y3 = G3(x1, x2, x3) ... (G is a polynomial equation) is believed to be a difficult problem, and is NP-hard and NP-complete for a random system. And it has been proved that the case of solving a system of 2rd-order polynomial equations (quadratic equations) is already difficult enough, and this question is called the Multivariate Quadratic Problem. This fact can be used to construct public-key cryptography. However, because the system cannot be random, it's not NP-hard or NP-complete (there is no system that is NP-hard in the entire study of cryptography, otherwise, how do you decrypt it...), but we believe that we can construct a system that is difficult to solve practically. Unfortunately, attempts on creating public-key encryption algorithms is largely unsuccessful, but there are successful digital signature schemes, such as Oil and Vinegar. Again, LARGE pubkey. * Hash-based Cryptography This scheme is proposed by Ralph Merkle in the late 70s, and remains unbroken today. First, generate 2^n pairs of random public and private keys (X, Y), and hash all private keys, let's say we have 4 keypairs. Placing these hash values Y0, Y1, Y2, Y3 at the bottom of a binary tree as leaves. We connect and hash the two surrounding values to obtain the next layer (think blockchains), so hash (Y0 + Y1), hash (Y2 + Y3), and built the tree recursively until we reach the root. H(H(H(Y0) + H(Y1)) + H(H(H(Y2) + H(Y3))) ... 1 node ^ ^ H(H(Y0) + H(Y1)) H(H(Y2) + H(Y3)) ... 2 nodes ^ ^ ^ ^ H(Y0) H(Y1) H(Y2) H(Y3) ... 4 nodes To sign a message, simply select an unused keypair (X, Y) to create the signature. The signature also contains additional information to show that the (X, Y) can be traced to the root of the Merkle Tree (think Bitcoin Wallet?). It has been proved that the its security can be reduced to the security of the underlying hash function. XMSS is such a system, and there is already an RFC standard for it. OpenSSH contains an implementation that you can use now today. The problem is its large keysize and limited number of signatures, and more importantly, it's stateful. Key reuse is FATAL. DJB has an attempt to make a stateless version, called SPHINCS. * Code-Based Cryptography This approach uses the difficulties on decoding error-correction code. Decode a general linear code is NP-hard. First, select a system of code that is easy to decode for us, as the private key, and transform it to a obscured form, as the public key. A classic algorithm is McEliece, it's known since the late 70s, as old as the original Diffie-Hellman, and still remains unbroken today, but it uses binary Goppa codes which requires LARGE keys. * Supersingular Elliptic Curve Isogeny cryptography The math is even beyond description to a layman like me. Basically, "isogeny" is a mathematical structure in abstract algebra, and we can find a bunch of supersingular elliptic curve in the same isogeny, and use the property of this isogeny to encrypt data. Just like the ordinary elliptic curve cryptography, which we use a bunch of points on the same curve and use the property of this group to encrypt data. An example of such algorithm is SIDH, and it's a new candidate for post-quantum Diffie-Hellman exchange, but requires a lot more CPU time.
ninguem2 7y ago
Can we estimate how much energy would a server farm of quantum computers (capable of doing something useful) need?
- whatshisface 7y ago
  Yes, but it would be kind of like Charles Babbage estimating how much coal would have to be burnt to power the Analytical Engine.
  - ninguem2 7y ago
    Well, if it's going to take 150 years to get to that point, maybe they should stop with the hype already.
zadkey 7y ago
Technology is mostly neutral morally* It's good in the hands of ethical people. It's bad in the hands of unethical people. Nothing about quantum computing changes this fundamental premise. I would say that the scale of good or bad that can from using quantum computing is much higher than other upcoming technologies. But beyond that, nothing is particularly different than any other new technology in this regard. *When I say technology here I am referring to over-arching technologies not specific applications. E.G. Nuclear technology in general, not nuclear power or nuclear weapons specifically.
nathias 7y ago
Technology is not morally neutral, it is always immediately good (as a new tool that extends our agency) but can be of course used to cause greater evil. Quantum supremacy is one of the greatest things humanity will have ever achieved, right there with the scientific revolution and abolishing the institution of infanticide.
yarrel 7y ago
Writing is a technology.

82 points by weinzierl 7y ago

Article Preview: This morning a humanities teacher named Richard Horan, having read my NYT op-ed on quantum supremacy, emailed me the following question about it: ``` Is this pursuit [of scalable quantum computation] just an arms race? A race to see who can achieve it first? To what end? Will this achievement yield advances in medical science and human quality of life, or will it threaten us even more than we are threatened presently by our technologies? You seem rather sanguine about its possible development and uses. But how close does the hand on that doomsday clock move to midnight once we “can harness an exponential number of amplitudes for computation”? ``` I thought this question might possibly be of some broader interest, so here’s my response (with some light edits). Dear Richard, A radio interviewer asked me a similar question a couple weeks ago—whether there’s an ethical dimension to quantum computing research. I replied that there’s an ethical dimension to everything that humans do.

Beltiras 7y ago

In my opinion Scott was really generous even answering. Horan makes no attempt at supporting his claim that QC will move us closer to midnight on the Doomsday Clock.

brudgers 7y ago
Horan is not claiming those things. Horan is wondering if the experts have considered those things. Scott's hand waving answer suggests that "no the experts have not." Engineering professionalism entails formal assessment of the risks. The burden of proof is on the engineer. Without that, it's astrology not engineering.
- Beltiras 7y ago
  Quoting Horan: But how close does the hand on that doomsday clock move to midnight once we “can harness an exponential number of amplitudes for computation"? Looks like a claim to me.
  - drewbug 7y ago
    but it ends with a question mark?
    - Beltiras 7y ago
      Implicit in the question.
      - drewbug 7y ago
        Yeah, you're right.
- gus_massa 7y ago
  It's a standard trick to sound smart. Just ask if the new thing have some unintended consequences. What is the cost of asking this for every new technology? Relevant xkcd https://xkcd.com/1215/ https://xkcd.com/1215/
  - deleted 7y ago
    [deleted]

tyri_kai_psomi 7y ago

I’m no fan of Trump, but the false moral equivalence parenthetically made of Trump to Xi Jinping who jails journalists for even expressing a semblance of dissent on social media tells you all you need to know about what Scott’s opinion on morality is worth.

pjc50 7y ago
Trump has condemned journalists often enough; he only lacks the absolute power necessary to jail them.
- utternerd 7y ago
  It is acceptable to condemn others you disagree with, it is not acceptable to throw them in a cage.
  - pjc50 7y ago
    e.g. https://www.bbc.co.uk/news/world-us-canada-48696131 https://www.bbc.co.uk/news/world-us-canada-48696131 - it's an empty threat, but it's still a threat.
KevinEldon 7y ago
I read that as The Americans, The Russians, or The Chinese with their current leaders written in as stand-ins.
- jonfw 7y ago
  The false moral equivalence of american government with the totalitarian dictatorships of China and Russia is extremely misguided.
  - tzs 7y ago
    Domestically, yes. Internationally, no. The US has a long history, comparable to if not more extensive than either China or Russia, of supporting totalitarian regimes in other countries. When accessing the potential danger of a new technology, for a large number of ordinary people in a lot of places around the world the chances of it being misused by the US against them is as likely as it being misused by Russia or China against them, and so lumping those three together is not unreasonable.

ohduran 7y ago

Nice take. It feels like the underlying question is "what should humans make a priority?". But we lack hindsight: it's a multi-armed bandit problem[0]. So the strategy should be in this case: let's try, and move towards what benefit us the most, and run away progressively from those things that aren't doing so. Of course, how do we define "benefit" is the tricky part that's left to the reader... [0] https://en.wikipedia.org/wiki/Multi-armed_bandit https://en.wikipedia.org/wiki/Multi-armed_bandit

Upvoter33 7y ago

I think you could ask this about all of science and invention - it is hard to know what the outcomes will be with any new knowledge.

Deestan 7y ago
http://dresdencodak.com/2009/09/22/caveman-science-fiction/ http://dresdencodak.com/2009/09/22/caveman-science-fiction/

scotchmi_st 7y ago

Personally I find it really irritating that so many people, such as the humanities teacher, suggest that technology has made life on Earth worse recently like it’s a commonly-understood truth. Yes there are problems with a handful of companies right now, but for the most part life has been improved for the vast majority of people in the world thanks to things like mobile phones.

gnode 7y ago
I don't think the concern here is the abuses of companies, or technologies like mobile phones. The concern is technologies like thermonuclear weapons (much worse than even nuclear weapons used against Japan), which we are just very lucky have so far not been used in earnest. I think it is a commonly-understood truth that those technologies present an existential threat to society, if not all humanity. Artificial intelligence is assumed by many to present such a threat (i.e. Terminator-style intelligence singularity scenario). Many speculate that applications enabled by quantum computing could also be similarly dangerous.
- chr1 7y ago
  There is also an argument that nuclear weapons were actually a greatest good for humanity, as they prevented wars between countries that have them.
- onepointsixC 7y ago
  Yet those thermonuclear weapons have been largely responsible for the long peace. [1]: https://en.wikipedia.org/wiki/Long_Peace https://en.wikipedia.org/wiki/Long_Peace
DrAwdeOccarim 7y ago
Why is that? In myself I see a common thread of where I recall "bad" things more strongly than "good" things. Is it an evolutionary benefit kind of thing where avoid bad things is much better than running toward good things because if you're dead it's much more permanent than if you're happy?
khawkins 7y ago

coldtea 7y ago

>The morality of that, of course, could strongly depend on whether the codebreakers are working for the “good guys” (like the Allies during WWII) or the “bad guys” (like, perhaps, Trump or Vladimir Putin or Xi Jinping). Yeah, not so sure about that. The allies might have been the "good guys" in WWII, but before and after they have enslaved 1/3rd of humanity as subjects in their colonials empires. And they have been busy making enemies, toppling governments, meddling, dividing and conquering, etc all around the globe before and after WWII, and during the Cold War. So, yeah, unless we compare to bona-fide Nazis, color me unimpressed with the idea that some group is so much better to unlock QC... Besides, wasn't Germany itself, with tons of ex-Nazi leaders, sympathizers, and supporters in all areas of post war leadership [1], best pals with said Allies a mere few years after the war? (as West Germany was a good asset to have for Cold War purposes (and East Germany for USSR for the same) Let's say the good and bad guys are in superimposition, as finger-pointing the fashionable names to be against in US politics du jour (Trump, Putin, Xi) doesn't really inspire confidence... [1] So much that a big demand of younger germans in the 60s and 70s was the "denazification" of the country (I'm not speaking here of the namesake half-hearted allied attempt).

matheusmoreira 7y ago

> But in any case, there’s already a push to switch to new cryptographic codes that already exist and that we think are quantum-resistant. Hopefully this will happen soon. I don't know of any quantum-resistant ciphers though.

hannob 7y ago
> I don't know of any quantum-resistant ciphers though. If you know them is however quite irrelevant. But if you want to enlighten yourself: https://www.nist.gov/news-events/news/2019/01/nist-reveals-26-algorithms-advancing-post-quantum-crypto-semifinals https://www.nist.gov/news-events/news/2019/01/nist-reveals-2...
nullc 7y ago
> I don't know of any quantum-resistant ciphers though. Almost all widely used symmetric cryptography is more or less quantum resistant already. Hash based signatures are the obvious quantum resistant signature, except where their size precludes them-- ( https://sphincs.org/ https://sphincs.org/ for a good example). For key agreement and asymmetric encryption the story is more complicated. Classical error correcting code based cryptography has a lot of reasons to feel positive about it security, but the public keys are large enough to make them inapplicable to many applications. ( https://classic.mceliece.org/ https://classic.mceliece.org/ for a good example ) For communications efficient key agreement or various zero-knowledge proofs other than signatures the field is much more complicated and the trade-offs less clear. There are a bunch of candidates in the NIST PQ contest, from several different distinct classes of hard problem. ( https://csrc.nist.gov/Projects/Post-Quantum-Cryptography https://csrc.nist.gov/Projects/Post-Quantum-Cryptography )

DrAwdeOccarim 7y ago

"Today, of Americans officially designated as "poor," 99 per cent have electricity, running water, flush toilets, and a refrigerator; 95 per cent have a television, 88 per cent a telephone, 71 per cent a car and 70 per cent air conditioning. Cornelius Vanderbilt had none of these." --Matt Ridley in "The Rational Optimist: How Prosperity Evolves"

slumdev 7y ago
I don't like this trope because it obscures the one thing that wealthy people know and non-wealthy people don't. Money is time. It's not gadgets or electricity or running water or toilets. It's time for yourself, your family, your religion (if you have one), and whatever hobbies make you tick. If you're on the hook to do someone else's bidding for 8+ hours a day, you are not wealthy, no matter how much they're paying you. Today's poor are worse-off than those in times past regardless of whatever trinkets they have. In almost every culture and occupation throughout history up to the industrial revolution, working people have never spent 8+ hours a day, year round, in servile labor. It's absurd. Regardless of how many Scooby Snacks you're so generously awarded by today's silicon robber barons, you will be poor until you stop measuring your life in trinkets and start measuring it in time.
- jcranberry 7y ago
  I'm not sure I buy that. Would you consider doctors significantly poorer than most other professions? Or surgeons at the least.
  - slumdev 7y ago
    Doctors are a rare breed. Now that the money isn't what it used to be (for most specialties, and in proportion to the cost of education), very few go into it as a "lifestyle profession". It attracts only the workaholics. Same with law.
    - jcranberry 7y ago
      That matches up with my experience with them.

scroot 7y ago

> A quantum computer is not like a nuclear weapon: it’s not going to directly kill anybody This is, of course, not the only problem with nuclear weapons (and by extension the science and technology that created them). First, there are several indirect ways that a single nuclear detonation could kill people. Second, the realization of nuclear weapons create a world in which nuclear war is possible -- one where mass detonations could alter the planet so radically that there would be innumerable indirect threats to everyone. Third, consider the way that the amassing of nuclear weapons so altered the geopolitical landscape, and what the effects were. This is precisely what the letter-writer is hinting at -- that we should be competent enough to strongly consider possible unintended consequences. Despite the prominent stream of thought on this site, no particular technology is in itself "inevitable." We have the capability, collectively, to choose whether or not to pursue something.

rcoveson 7y ago
> We have the capability, collectively, to choose whether or not to pursue something. This is the coordination problem to end all coordination problems. Is there an example in history of civilization turning its collective back on some scientific pursuit in fear of its potentially negative consequences? It seems close to impossible. There are too many different value structures out there, and there’s too much money on offer to anyone who can give any government or large corporation an advantage over its competitors. You may be able to convince a few researchers today, but as soon as China has the slightest breakthrough towards X or Y technology, most of those who signed the pledge will be tripping over themselves to get cracking on the problem.
- scroot 7y ago
  > Is there an example in history of civilization turning its collective back on some scientific pursuit in fear of its potentially negative consequences? It seems close to impossible. First we should ask: is this a "scientific" pursuit in the first place? Or, rather, are we describing the creation of some mechanisms (based themselves on scientific discovery) that can be used for all kinds of purposes, among them, yes, future scientific practice? Computing leverages scientific discovery, and aids in its practice, but is itself not science. Second, and at the risk of sounding trite, we can also ask "is there an example in the history of civilization of someone flying before the Wright brothers?" or "is there an example in the history of civilization of a world governing body before the 20th century?" The very promise of democracy, in general terms, is that we should, in fact, be able to make large decisions together on a society-wide scale. And because that is, ostensibly, the highest level through which we coordinate, we can should also be able to direct how our democratic institutions help us achieve those aims. If your position is that money, corporate influence, or government corruption prevent such coordination, you are certainly correct. But these are not "natural law." We have the ability -- however likely -- to deal with those problems. Otherwise, what's the point? > You may be able to convince a few researchers today, but as soon as China has the slightest breakthrough towards X or Y technology, most of those who signed the pledge will be tripping over themselves to get cracking on the problem. We are not limited to pledges. But even in that case, it is then up to those scientists who turn a dime to deal with their own potential moral failings.

segfaultbuserr 7y ago

> But in any case, there’s already a push to switch to new cryptographic codes that already exist and that we think are quantum-resistant. An actual scalable QC on the horizon would of course massively accelerate that push. Wikipedia has a good review on major subdivisions of Post-Quantum Cryptography. * https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography In short, in additional to integer factorization and (elliptic) discrete logarithm, there are a lot of others hard problems that can be used to construct public key encryption algorithms. * Lattice-based cryptography A "lattice" is a mathematical structure in abstract algebra. The study of it originally came from the theoretical analysis in solid-state physics on the structure of crystals, and can be understood as a matrix of evenly spaced "dots" in space. Formally, it's a discrete subgroup of an addictive group in an n-dimensional space. * * * * * * * * * * * * * * * * (This is a lattice) There exists several problems about them that are believed to be extremely difficult, called Lattice Problems. One well-known example is the Shortest Vector Problem: given a lattice L in vector space V and a norm N, find the shortest non-zero vector in V, measured by N, in L. There are fast approximate solutions, but under certain circumstances, this is an NP-hard problem, so we assume that we can construct a system, that is difficult to solve, although it's not HP-hard. NTRU is an algorithm that utilized a similar problem about lattice, proposed in 1997, no fundamental problems have been found in the original algorithm, so even after 20 years, it remains unbroken today. OpenSSH contains an implementation that you can use now today. But it requires LARGE (many KiB) public key - there's a large system of polynomials. Also, parameter selection is a question. * Learning With Errors (LWE) In theoretical machine learning, there's a problem called "Learning with Errors". I don't understand this problem well, but basically, we have a system of linear polynomial equations, but with random "noise". Solving this system of equations is believed to be extremely difficult. And interestingly, Oded Regev proved this problem is as difficult as some of the worst Lattice Problems. So LWE is considered a branch of Lattice-based Cryptography. There is also a variant of this problem, called Ring-RWE, which is more efficient for cryptography. Example includes Google's NewHope ciphersuits. Again, LARGE pubkey. * Multivariate cryptography Solving a system of polynomial equations with many variables in a finite field F, y1 = G1(x1, x2, x3) y2 = G2(x1, x2, x3) y3 = G3(x1, x2, x3) ... (G is a polynomial equation) is believed to be a difficult problem, and is NP-hard and NP-complete for a random system. And it has been proved that the case of solving a system of 2rd-order polynomial equations (quadratic equations) is already difficult enough, and this question is called the Multivariate Quadratic Problem. This fact can be used to construct public-key cryptography. However, because the system cannot be random, it's not NP-hard or NP-complete (there is no system that is NP-hard in the entire study of cryptography, otherwise, how do you decrypt it...), but we believe that we can construct a system that is difficult to solve practically. Unfortunately, attempts on creating public-key encryption algorithms is largely unsuccessful, but there are successful digital signature schemes, such as Oil and Vinegar. Again, LARGE pubkey. * Hash-based Cryptography This scheme is proposed by Ralph Merkle in the late 70s, and remains unbroken today. First, generate 2^n pairs of random public and private keys (X, Y), and hash all private keys, let's say we have 4 keypairs. Placing these hash values Y0, Y1, Y2, Y3 at the bottom of a binary tree as leaves. We connect and hash the two surrounding values to obtain the next layer (think blockchains), so hash (Y0 + Y1), hash (Y2 + Y3), and built the tree recursively until we reach the root. H(H(H(Y0) + H(Y1)) + H(H(H(Y2) + H(Y3))) ... 1 node ^ ^ H(H(Y0) + H(Y1)) H(H(Y2) + H(Y3)) ... 2 nodes ^ ^ ^ ^ H(Y0) H(Y1) H(Y2) H(Y3) ... 4 nodes To sign a message, simply select an unused keypair (X, Y) to create the signature. The signature also contains additional information to show that the (X, Y) can be traced to the root of the Merkle Tree (think Bitcoin Wallet?). It has been proved that the its security can be reduced to the security of the underlying hash function. XMSS is such a system, and there is already an RFC standard for it. OpenSSH contains an implementation that you can use now today. The problem is its large keysize and limited number of signatures, and more importantly, it's stateful. Key reuse is FATAL. DJB has an attempt to make a stateless version, called SPHINCS. * Code-Based Cryptography This approach uses the difficulties on decoding error-correction code. Decode a general linear code is NP-hard. First, select a system of code that is easy to decode for us, as the private key, and transform it to a obscured form, as the public key. A classic algorithm is McEliece, it's known since the late 70s, as old as the original Diffie-Hellman, and still remains unbroken today, but it uses binary Goppa codes which requires LARGE keys. * Supersingular Elliptic Curve Isogeny cryptography The math is even beyond description to a layman like me. Basically, "isogeny" is a mathematical structure in abstract algebra, and we can find a bunch of supersingular elliptic curve in the same isogeny, and use the property of this isogeny to encrypt data. Just like the ordinary elliptic curve cryptography, which we use a bunch of points on the same curve and use the property of this group to encrypt data. An example of such algorithm is SIDH, and it's a new candidate for post-quantum Diffie-Hellman exchange, but requires a lot more CPU time.

ninguem2 7y ago

Can we estimate how much energy would a server farm of quantum computers (capable of doing something useful) need?

whatshisface 7y ago
Yes, but it would be kind of like Charles Babbage estimating how much coal would have to be burnt to power the Analytical Engine.
- ninguem2 7y ago
  Well, if it's going to take 150 years to get to that point, maybe they should stop with the hype already.

zadkey 7y ago

Technology is mostly neutral morally* It's good in the hands of ethical people. It's bad in the hands of unethical people. Nothing about quantum computing changes this fundamental premise. I would say that the scale of good or bad that can from using quantum computing is much higher than other upcoming technologies. But beyond that, nothing is particularly different than any other new technology in this regard. *When I say technology here I am referring to over-arching technologies not specific applications. E.G. Nuclear technology in general, not nuclear power or nuclear weapons specifically.

nathias 7y ago

Technology is not morally neutral, it is always immediately good (as a new tool that extends our agency) but can be of course used to cause greater evil. Quantum supremacy is one of the greatest things humanity will have ever achieved, right there with the scientific revolution and abolishing the institution of infanticide.

yarrel 7y ago

Writing is a technology.