[HN Gopher] Cryptocurrency mining using integrated photonics
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Cryptocurrency mining using integrated photonics
Author : neopba
Score : 84 points
Date : 2021-10-01 08:10 UTC (14 hours ago)
(HTM) web link (phe.tue.nl)
(TXT) w3m dump (phe.tue.nl)
| Freskis wrote:
| [deleted]
| neopba wrote:
| That's unfortunate. Just FYI here is a related story I posted
| some time ago https://news.ycombinator.com/item?id=27205918
|
| Peace
| kybernetikos wrote:
| Public blockchain systems are distributed databases that anyone
| can submit write transactions to and where you don't need
| preauthorisation to join the system. In order to avoid the
| network being taken over by sybil attacks, it's necessary for
| participation to be based on locking up / committing / consuming
| something rare. Anything that becomes cheap or easy is not
| suitable for basing participation on.
|
| So far I know of systems using computational work (PoW),
| ownership of cryptocurrency (PoS), or storage space as that rare
| resource. The idea of using photonics to create a low energy
| 'proof of time' basis is interesting but there would still be
| difficult economic considerations. If acquiring the photonics is
| too hard, then you've got a centralised system, if it's too easy
| then the sybil resistance and environmental impact benefit goes
| away (because control of the system devolves into 'who can
| acquire the most hardware' incentivising massive production).
|
| Perhaps surprisingly, improving the cost efficiency of the work
| done by a traditional PoW blockchain doesn't reduce its energy
| usage, because the usage is determined by a competitive market
| place driven by supply & demand, not by a fixed amount of work
| needing to be done. Increasing the cost efficiency of the
| calculations just results in the blockchain doing more
| calculations.
|
| A huge chunk of the cost is in the electricity used, so power
| efficiency and cost efficiency are very very similar. Ultimately
| I don't think you can improve matters much by attacking power
| efficiency of the calculations. You may be able to move the
| economic balance point between upfront/ongoing costs by requiring
| more or more expensive hardware, but reducing ongoing electricity
| usage isn't a clear win if it's produced more waste and power
| usage during the creation and ultimate disposal of the hardware.
| mistrial9 wrote:
| > Ultimately I don't think you can improve matters much by
| attacking power efficiency of the calculations.
|
| citation
| acjohnson55 wrote:
| One way I've come to think of it is that Sybil resistance comes
| from having the next block producer chosen by a raffle, with
| some resource used as the ticket. PoW is an example of the
| resource being exogenous to the system and PoS is an example of
| the resource being endogenous.
|
| A problem I see with both is that they are inherently
| plutocratic, in that the wealthiest participants will have
| greater economies of scale in the resources they devote to the
| block production process.
| kybernetikos wrote:
| This is true, however it's also not an unusual feature -
| pretty much every capitalist society has the characteristic
| that those with capital can gain more capital with a minimum
| of additional work.
|
| Alternatives that don't have that feature to at least some
| extent would be regarded as very radical, and difficult to
| implement.
| ordinaryradical wrote:
| This has already been implemented in at least one other
| crypto successfully. See: Nano (formerly Raiblocks).
|
| The crypto community, however, seems to have a very narrow
| focus on reproducing these plutocratic systems and
| incentives because everyone wants that power for themselves
| and wants to be first in whatever the Next Big Thing is.
| Crypto development as a whole seems to be hampered by these
| incentives and by an excessive focus on the original
| technologies of Bitcoin as opposed to its original aims.
| shanusmagnus wrote:
| I don't think it's an excessive focus on BTC technology,
| so much as that BTC abstracts the core issues to their
| fundamental essence and forces the tradeoffs on those
| terms, without obfuscating them. For instance, POW is
| extremely clear: you make a sacrifice to create blocks /
| mint transactions. It's almost biblical -- the game
| theory doesn't work without the sacrifice, and sacrifice
| is, tautologically, a tradeoff of one precious thing for
| another. All other crypto projects either want free lunch
| someplace, or make very different tradeoffs and
| assumptions.
| meowface wrote:
| No, I think most people (as in, core developers) just
| want whatever can actually be relied upon. If there were
| a silver bullet consensus algorithm that was
| decentralized and secure and also far less
| wasteful/plutocratic, everyone would probably switch to
| it.
|
| The idea that there's an easy, superior solution on the
| other side's grass and bad motives are just keeping
| people locked into a bad system is a convenient
| narrative, but rarely true. I don't know the details
| about Nano, but my guess is the reason other
| cryptocurrencies haven't adopted their algorithm is
| because they don't think it's sufficient, for whatever
| reason.
| ordinaryradical wrote:
| Nano/Raiblocks has been around for years, the original
| developer was also one of the first to work on Bitcoin,
| apparently, and the network has been live for some years
| and successfully transacting.
|
| I don't think it's a matter of the technology being
| unproven or unreliable. There was recently a 22 million
| dollar transaction that was both feeless and recorded to
| the network in <5 seconds.
|
| It seems obvious though that to adopt the protocol means
| sacrificing a plutocratic winner-take-all mining regime
| and everyone in the crypto space wants to be that winner.
|
| Why go through the trouble of developing a photonic
| mining system if there's already a viable alternative to
| PoW/PoS in the real world being used? Why all these
| outlandish schemes to "green" PoW networks (that never
| come to fruition) when there's a viable technology
| transacting at a literal 6 millionth of the cost of a
| single btc transaction?
|
| At a certain point, you begin to see that a large part of
| this space is not committed to the aims they espouse but
| to a kind of delirious financial brinksmanship that
| yields little in the way of progress but makes small
| numbers of people very wealthy.
| meowface wrote:
| I'm sure there are many people who share the mentality
| you describe, but I don't think it applies to most core
| developers of cryptocurrency protocols, and such
| developers also don't make more money the more expensive
| mining is.
| nybble41 wrote:
| > Why go through the trouble of developing a photonic
| mining system if there's already a viable alternative to
| PoW/PoS in the real world being used?
|
| Nano has some interesting ideas but also some fairly
| obvious flaws, most notably the fact that there is no
| built-in economic incentive to run a Representative node
| and participate in the voting. Running a node is an
| expensive operation (in CPU time, memory, and bandwidth)
| and the protocol basically leaves this important function
| up to individual enthusiasm or goodwill. As a result
| there are a limited number of active voting nodes making
| decisions for the network.
|
| The faucet-based initial distribution of Nano (XRB) is
| also arguably less egalitarian than Bitcoin's PoW-based
| mining rewards. If you weren't aware of Nano (RaiBlocks)
| while they were running the faucet then you had no chance
| to participate in that initial distribution. This is not
| quite as bad as full pre-mining where _all_ the initial
| coins go to the developers and other may or may not be
| able to mine more later at a higher difficulty, but it
| seems likely that the developers and other early adopters
| would have received the majority of the output from the
| XRB faucet, which by design is all the XRB which will
| ever be produced.
| kybernetikos wrote:
| From what I know of Nano, I don't believe it would work
| correctly under situations where it was being attacked.
| wyager wrote:
| > ownership of cryptocurrency (PoS)
|
| The problem is that PoS commitment isn't binding. You can
| always stake your money, then if you don't like the outcome,
| you can just pretend the first stake never happened and do it
| again. Cf "grinding" attack. PoW is unique in that any
| _claimed_ commitment corresponds to a _real, physical,
| irrevertable_ commitment.
|
| > or storage space as that rare resource.
|
| Every storage coin so far has been some sort of DINO scam. The
| most interesting one is Chia but it's absurdly complicated, and
| I think that complication might mask some
| centralization/vulnerability. For example, the reliance on
| "time lord" nodes strikes me as very questionable.
| lt wrote:
| What's a DINO scam? Couldn't google anything relevant.
| wyager wrote:
| DINO stands for "decentralized in name only", which refers
| to the shockingly common case of a crypto-thing advertising
| itself as decentralized when in fact it is controlled by a
| single entity or cartel.
| danvayn wrote:
| I think widespread institutional adoption of crypto is pretty
| important in this regard.Operating a photonic miner being hard
| provides more incentive to be a part of those 'mining' it, as
| you might expect. So, if it's beyond average user scope but
| within say .1-1% of a companies budget and could create massive
| dividends, why shouldn't they invest in this?
|
| It can be a little gross to consider, because no ones like idea
| of 'the rich getting richer', but that isn't really different
| from what happens today, anyways. What matters most is that the
| system has a lot of nodes to work with, and that can still
| happen here if there's enough adoption in this scenario.
|
| Not to mention that it should be hard to abuse your control in
| a public blockchain system. Governments could require companies
| to have an use photonic miner operating license and revoke it
| if they did something like this, for example. I think its a
| decent middle ground between centralized and decentralized. And
| (should?) produce less electric waste overall. I'm not sure, I
| don't really know much about photonics.
| tsimionescu wrote:
| Using PoW crypto at all creates massive waste for no
| productive use. In a world struggling to avoid catastrophic
| climate changes, it is completely irresponsible, and should
| be stopped instantly.
|
| Not to mention, crypto currencies are worse than traditional
| currencies in every way: much more wasteful than the whole
| global banking system for a tiny tiny tiny fraction of a
| percentage of the number of transactions, much more
| centralized in several ways, deflationary, impossible to
| control if they spiral. There is no reason to keep this
| charade going.
| RustyConsul wrote:
| 'Impossible to control'.
|
| Born to a generation that has lost faith in governments,
| this is why i have crypto.
| Geee wrote:
| This isn't actually true at all. Climate problems are
| caused by competition between governments and their pursue
| for growth, which forces everyone to consume and produce
| more than is necessary. Under the current economic system,
| natural catastrophe is inevitable. Bitcoin actually fixes
| this, because it makes it impossible for governments to
| enforce growth through money supply manipulation, which
| they have to do to compete with each other.
| adrianN wrote:
| The current economic system is compatible with a carbon
| neutral world. We managed to ban all kinds of destructive
| things that provide (short-term) economic benefits
| without changing our economic system.
| tromp wrote:
| > worse than traditional currencies in every way
|
| Yes, they're worse in many ways, but that is exactly the
| design decision they made in order to be better in one
| particular way; to be censorship resistant (and
| permissionless).
|
| Not all are deflationary; many have a tail emission that
| makes the supply dis-inflationary.
| tsimionescu wrote:
| Nothing is censorship resistant against a determined
| censor. If crypto sees more and more adoption, exchanges
| and companies accepting it will likely get pushed to
| implement KYC and AML just as much as banks are.
| incrudible wrote:
| Proof of work is wasteful in the same sense that having
| banks is wasteful. Imagine what it takes to operate a
| banking institution. It's not just electricity. It would be
| "efficient" to just write the word "bank" on a shack and
| then have one or two workers "guard" over all the deposits.
|
| Unfortunately, nobody would be willing to use such a bank.
| Actual banks that people use need to spend a lot of money
| just on maintaining the charade of being proper custodians.
| Yet, they can still lose your deposit, in which case they
| rely on the government to bail them out.
|
| Perhaps proof-of-stake is something that can mostly replace
| proof-of-work, but the proof is in the pudding.
| tsimionescu wrote:
| > Actual banks that people use need to spend a lot of
| money just on maintaining the charade of being proper
| custodians. Yet, they can still lose your deposit, in
| which case they rely on the government to bail them out.
|
| The major difference is that, collectively, the world's
| banks are a decentralized system that processes billions
| of times more transactions every hour than Bitcoin and
| other major PoW coins have ever executed, while offering
| many services which are impossible to offer through
| Bitcoin - loans, insurance, the ability to recover your
| money from a fraudulent transaction, and many others.
|
| Replacing this entire centuries old system is something
| that no one wants - not the left, not the right, nor the
| vast vast majority of crypto owners, who are just in it
| for a quick buck.
| goohle wrote:
| "No office", app-only banks exists. One such bank is
| popular in my country.
| casi18 wrote:
| If we want to bring climate change under control then
| coordination and communication tools that cross national
| borders are necessary. That is what many of us working in
| crypto are focused on, you might not yet value it, but we
| do.
|
| How do we collectively, as a planet, decide what is
| acceptable usage of energy and what isn't? Who gets to use
| machines and who doesn't? And how do we do that in a way
| that isn't authoritarian, and held together with violence?
|
| Is it wrong to use my gpu playing video games all day, or
| is the moral panic only applying to certain uses of
| computers?
|
| When you say it should be stopped instantly you should
| clarify what you mean by that, what action do you see being
| taken?
| smus wrote:
| >Is it wrong to use my gpu playing video games all day,
| or is the moral panic only applying to certain uses of
| computers?
|
| Is it wrong for you to leave a warehouse full of
| computers idling to play a computer game? Yes. This is
| one of the more outrageous false equivalences I've seen.
|
| It stops being a moral panic when crypto consumes more
| electricity than the entire nation of Argentina.
| tsimionescu wrote:
| If every person on the planet were using their GPU to
| play a few hours every day, they would probably not reach
| the amount of energy used by the Bitcoin blockchain
| alone.
|
| All of the things you are citing require cooperation and
| discussion and democratic discourse. An algorithmically
| driven opaque protocol controlled by a handful of
| technocrats (the people developing the major clients and
| the ones running the major mining pools) is part of the
| problem, not a model for the solution.
|
| Not to mention, money as a means of exchange is simply
| not one of the problems standing in the way of stopping
| global warming. The biggest problems are caused by rich
| people who have calculated that they will not be
| personally impacted, who couldn't care less about the
| poor 90+% of the planet who will, and who have thus
| decided to prioritize increasing their wealth today over
| any sort of urgent changes. It is also perpetuated by
| organizational systems put in place a long time ago
| (mainly for profit corporations with lobbying power) that
| have the same goals - short term profit over any other
| consideration.
| CryptoPunk wrote:
| >>Not to mention, crypto currencies are worse than
| traditional currencies in every way
|
| You've never been denied financial services due to
| discriminatory policies, or you would not claim that.
|
| Everything needs to migrate to the public blockchain:
| banking, online markets, social media platforms, etc.
| Giving a handful of corporations and governments control
| over almost every aspect of every one's lives is dangerous
| and corrupting.
| tsimionescu wrote:
| Yes, much better to give such control to an algorithm and
| protocol written and controlled by a handful of engineers
| and mining pool owners.
|
| And make no mistake: in a state that allows or encourages
| financial institutions to discriminate, you will
| eventually be discriminated against with Bitcoin as well.
| The state may not have caught up to the technology yet,
| but social problems can't be fixed with technology.
| CryptoPunk wrote:
| The protocol is publicly defined, and immutable. There is
| no need to trust any engineers, or give them any control,
| just as you don't need to trust the developers of open
| source software in order to trust the software.
|
| And it is much harder for a state to ban a blockchain,
| than impose laws on centralized financial intermediaries
| that lead to rampant banking discrimination. The former
| will cost far more, in economic resources and political
| capital, to enforce.
| tsimionescu wrote:
| The protocol is not immutable, and there have been
| several changes to it in the early days, and several
| proposed changes that keep being discussed (such as the
| famous block size limit change). If the people developing
| the software and the major mining groups agree on a
| change, who will stop them?
| CryptoPunk wrote:
| It is extremely hard to organize a protocol change that
| succeeds in tampering with existing smart contacts, let
| alone eliminates the permissionless/neutrality guarantees
| of a public blockchain with significant adoption.
|
| For a public blockchain with as large a userbase as
| Ethereum, a protocol change that nullifies its neutrality
| and permissionless-ness would be nearly impossible for
| any group to push through.
|
| It's absolutely incomparable to traditional banks, with
| respect to the degree of resistance to interference from
| governments.
| kybernetikos wrote:
| > social problems can't be fixed with technology.
|
| Do you think that 'social problems can't be caused by
| technology'? Because if social problems can be caused by
| technology then surely they can solve them too.
| tsimionescu wrote:
| Yes, I also think social problems can't be caused by
| technology. Technology is neutral - if we're using it to
| do harm, it's harmful. If we're using it to help, it
| helps.
|
| Note that this is not 'guns don't kill people, people
| kill people'. Guns do kill people, so they must be
| regulated. The gun violence problem in the USA is not the
| fault of guns, it's the fault of the way US society
| chooses to regulate access to guns.
| mmmBacon wrote:
| I see these things and while interesting they are just a lab
| curiosity.
|
| From the paper: _By tuning the phase delays of each waveguide at
| each layer of the directional coupler mesh and the coupling
| region's effective optical length using heaters it should be
| possible to achieve an arbitrary unitary transfer matrix_
|
| As these phase sections are thermally tuned, they are slow and
| will have thermal crosstalk to their neighbors. While this is
| manageable it's not exactly fast to create a new matrix transfer.
| Additionally, these devices drift over time and operating
| temperature. Changes over time are due to changes in local stress
| that cause refractive index to change. So this device as
| published has no ability to put the MZM bias into a known state
| and keep it there. Drift is a part of working with photonic
| devices and even when temperature controlled (very inefficient)
| they still need compensation. This compensation is the difference
| between a lab device and something that could be commercialized.
|
| Furthermore such devices have what we call parasitic reflections.
| When the phase is adjusted, the parasitic reflected phase is also
| adjusted creating an error in the output. For an analog computer
| that can only look at amplitude any numerical resolution would
| have to be coarser than the size of these parasitic reflections.
|
| This is just the tip of the iceberg. Yet none of these papers
| ever address these problems.
| jazzyjackson wrote:
| What's this about manufacturing photonic reservoir computers with
| old CMOS processes? We can do matrix multiplication with photon-
| buckets or what?
|
| Edit: I guess I'll read the paper for its intro to photonics, I
| haven't really heard of doing useful math with this stuff
| https://assets.pubpub.org/xi9h9rps/01581688887859.pdf
| mmmBacon wrote:
| Optical devices are physically large with waveguides about 1um
| and and most devices are a few hundred microns in size. The
| Mach Zehnders that they discuss are 100's of microns in
| physical size. So it's typical that silicon photonics are
| fabricated in older nodes in part because the resolution of
| advanced nodes is not needed and it's a lot cheaper to use the
| older nodes. Additionally the sweet spot for silicon photonics
| is a wavelength ~ 1.3um (1.5um) so the node resolution is
| sufficient for the wavelength used.
| mistrial9 wrote:
| HNews people - multiple, lengthy comments here claim that "due to
| competitive pressures" the "total energy used to mine will be the
| same" no matter how hashes are calculated.
|
| The challenge problem in BTC is to find a number below a
| threshhold that fits a pattern. The threshhold changes in a two
| week regime. Finding the number is not prescribed, only the
| threshhold. Where is the required energy use here?
|
| Please illuminate
| colechristensen wrote:
| The amount of mining being done would be driven by the price of
| mining (fixed + recurring) and the reward for mining.
|
| If you make mining cheaper you just get more mining, lowering
| energy usage per unit mining will increase the mining done to
| balance the reward.
|
| Actually lowering total energy usage would require lowering
| total reward or raising the price of energy.
| mistrial9 wrote:
| this is a sort of economic framing, but also, not the
| question
| jlokier wrote:
| It's hard to figure out what you really want to know, after
| many commenters have tried to explain why replacement
| mining technology doesn't reduce overall energy
| consumption, which was your broader line of questoning.
|
| So I will focus on this one part:
|
| > Where is the _required_ energy use here?
|
| Fundamentally, the hash calculation is designed so that
| energy consumption is proportional to required hashrate -
| regardless of hashing technology.
|
| The required hashrate is reactive. It's governed by the
| difficulty adjustment algorithm which reacts to economic
| competition on the blockchain as well as economic
| competition among miners, so as to create two decoupled
| markets with money nonetheless flowing between them, which
| incentivises miners to spend most of the fees offered by
| blockchain users on energy, regardless of how efficient the
| mining technology is per hash.
|
| So the required hashrate always adjusts until most of the
| mining fees offered by blockchain users gets spent on
| energy.
|
| If your question is, essentially, "why any energy at all",
| the answer is that calculating things using zero energy
| isn't possible. If your question is "why can't we come up
| with a way to calculate these numbers that's so efficient
| the system won't increase the difficulty to fully
| compensate", that might be possible, but it would require
| the brute-force algorithm assumption to be broken. That is
| a type of breaking cryptography. The cryptography is
| designed so that it uses energy proportional to the
| hashrate on _any_ type of computer. There is no known way
| around that. People try, of course; the incentives are very
| high for them to succeed.
|
| Merely building a faster computer won't do it. A photonic
| computer, for example, doesn't challenge this assumption at
| all. A computer a trillion times more energy efficient
| would not challenge this assumption either. My limited
| understanding tells me even a quantum computer doesn't
| challenge this assumption, because SHA256 hashing is not
| amenable to Shor's algorithm, and Grover's algorithm only
| divides the bit-difficulty in half, which the difficulty
| threshold adjustment would automatically compensate for.
|
| However, switching away from proof-of-work does change this
| assumption, and that's how to reduce the energy
| consumption.
|
| > this is a sort of economic framing, but also, not the
| question
|
| You cannot ignore the economic framing - it is a key
| technical part of the proof-of-work design.
|
| It is such an important and powerful effect, it has a
| technical name, _cryptoeconomic incentive_ , and it's
| treated as a critical _technical_ factor in all major
| blockchain designs.
|
| Although you can see it as a statistical or human effect,
| it is a strong and predictable effect. It is almost
| analogous to statistical mechanics, where we can calculate
| the properties of physical substances from underlying
| "random" individual behaviours, because the statistical
| ensemble behaves in a predictable way.
| colechristensen wrote:
| The energy usage comes from the economics, and can't be
| escaped. The growth of the global hashrate is driven by the
| profit margin between the mining cost and reward and
| growing overall mining costs drive btc prices higher.
| mistrial9 wrote:
| first reference:
|
| Majority is not Enough: Bitcoin Mining is Vulnerable; Ittay
| Eyal and Emin Gun Sirer, 2014
| RedNifre wrote:
| It's not about the energy usage, it's about the cost: If you
| make energy two times as expensive, you would half the mining
| being done and half the energy usage. If you introduced a 50%
| global mining tax, you would also half the mining and the
| energy usage. If you invent technology that can do twice the
| mining for the same amount of energy, you would get twice the
| mining and the same energy usage.
| jlokier wrote:
| - The total mining income is determined by how much blockchain
| users are willing to pay for blockchain services. It's
| determined by market demand for transactions on the blockchain,
| in a grand auction competing with other users.
|
| - There are two markets - competition between blockchain users
| offering fees in their grand auction, and competition between
| miners. These are strongly decoupled from each other by the
| difficulty threshold update algorithm. So the total mining
| income, offered by users and paid to miners, is independent of
| hashrate, number of miners, or mining technology. Miners don't
| change the total mining income, they can just compete to get a
| share of it.
|
| - Finding the hash number requires a brute force algorithm.
| There are shortcuts to do it significantly faster, but it is
| assumed there is no mathematical shortcut which avoids the
| brute force property. (Brute force means a particular
| mathematical property of the search algorithm, it does not say
| how fast or what kind of technology.)
|
| - No matter what technology is used to find the number, it
| requires _some_ energy, and in proof-of-work, due to the brute
| force property, the rate of energy consumed is proportional to
| the hashrate.
|
| - The required total hashrate automatically adjusts, via the
| difficulty threshold, so that a miner with X% of the total
| hashrate gets X% of the total network mining fees, no matter
| what technology they use.
|
| - A miner with X% of the total hashrate can spend anywhere from
| 0% to X% of the total network mining fees and remain
| profitable, depending on how energy efficient their rigs are.
| No more than X%; that would make a loss, so they would stop.
|
| - A miner with access to more energy efficient mining
| technology (lower rate of energy consumed per hash) will seek
| to maximise their profit by obtaining more mining rigs, if they
| can get them. When that technology is widely available,
| everyone will want it. The effect is to push up the total
| hashrate for everyone.
|
| - When the total network hashrate goes up, miners without the
| new technology cease to be profitable (they are spending the
| same but their X% has reduced due to the total hashrate
| increase, so they receive insufficient payment), and those have
| to stop mining unless they can get the new technology. Only
| miners with the new technology can afford to participate.
|
| - Therefore the network rapidly converges on the new
| technology.
|
| - The total spent on mining costs must be between 0 and the
| total mining income.
|
| - When the total spend on mining costs is much below the total
| mining income, and the new technology is widely available,
| someone sees a market opportunity and buys a mining rig. It
| works this way because the network has converged on the new
| technology, so it's a roughly level playing field to join.
|
| - This raises the hashrate, and pushes up the total mining
| costs, without changing the total mining income. This keeps
| happening and converges towards an equilibrium where the total
| costs are close to the total mining income. As long as there's
| someone seeing an opportunity to get a little for themselves.
|
| - Because much of mining costs is energy cost, the miner
| equilibrium is eventually reached when the total spend on
| energy is close to the total mining income.
|
| - Therefore, total energy consumption is roughly determined by
| the amount of energy that can be purchased for the total mining
| income.
|
| - As mentioned at the start, total mining income (before costs)
| is decoupled from all this mining business. So rolling out new
| mining technology doesn't change how much total income is
| available to spent on the whole blockchain mining network, and
| competitive self-interest among miners means most of that spend
| goes to energy.
| mistrial9 wrote:
| interesting! I will research on this and reply (it might take
| a few days)
| pavlov wrote:
| If an invention enables hashes to be computed 10x more
| effectively, miners aren't going to reduce their energy use by
| 90% -- they'll switch to the new equipment, increase their hash
| rate 10x, and keep using the available energy.
| 3np wrote:
| And, if they don't, this creates an opportunity for others to
| outcompete them (on average) by doing just that
| mistrial9 wrote:
| yes, agree it is roughly true that miners will very likely
| maximize their efforts.. this is not the question however
| tromp wrote:
| The difficulty D defines the expected number of double SHA256
| hashes E[H] = 2^32 * D that must be computed on average per
| block to meet the difficulty target, which according to the
| average efficiency of mining ASICs implies an average amount of
| energy to be used.
| mistrial9 wrote:
| first of all, difficulty D is a float, and there are no
| floats in the actual computation. Second, a float is not a
| number of hashes. bzzzzt
|
| edit- In plain English, this explanation is incorrect because
| it relies on floating point number D. Difficulty D is a
| convenience representation as float of the ratio of two very
| large integers; one of those large integers is the fixed MAX
| Target. The other vary large integer is varied by a
| prescribed formula, once every two weeks.
| tromp wrote:
| Indeed; as [1] says: What is the formula
| for difficulty? difficulty = difficulty_1_target /
| current_target (target is a 256 bit number)
|
| I simply used the fact that the difficulty_1_target (the
| MAX Target as you call it) needs an expected 2^32 double
| SHA256 hashes to meet.
|
| [1] https://en.bitcoin.it/wiki/Difficulty
| mistrial9 wrote:
| > expected 2^32 double SHA256 hashes
|
| yes, expected by.. some approximation of the current
| hardware to find the solution.. We are not at the answer
| yet
| tromp wrote:
| Nothing to do with hardware. Quoting again from that
| bitcoin wiki page: The highest possible
| target (difficulty 1) is defined as 0x1d00ffff, which
| gives us a hex target of 0x00ffff * 2**(8*(0x1d -
| 3)) = 0x00000000FFFF0000000000000000000000000000000000000
| 000000000000000
|
| As you can see a random hash has a chance of close to
| 2^-32 to satisfy that target.
| mistrial9 wrote:
| > Nothing to do with hardware
|
| use a pencil?
| OnlyRepliesToBS wrote:
| pls stop
| tromp wrote:
| oPoW FAQ from [1]
|
| 1. Is there reason to believe that the manufacturing of oPoW
| miners will be more decentralized than ASIC manufacturing
| currently?
|
| There are no guarantees in decentralized networks, but we think
| all evidence points to oPoW creating a more decentralized
| network.
|
| a. Cost of entering oPoW hardware manufacturing will be much
| lower due to Silicon Photonics using old CMOS nodes (~90 or 220
| nm vs. ~7 nm for transistors).
|
| b. Removing electricity prices from the mining equation means
| that miners do not have to concentrate in regions with cheap
| power or depend on the sanction of governments that control most
| energy sources.
|
| 2. What other costs would replace energy?
|
| Hardware depreciation
|
| 3. Why create Heavy Hash, why not just compute SHA256 optically?
| This accomplishes the same goal without any changes to the
| Bitcoin codebase.
|
| Many have tried... there is a large economic incentive. Analog
| optical computing is limited in the types of computations it can
| do efficiently. It's much more feasible to design the PoW around
| those limitations.
|
| 9. When will optical mining hardware be available?
|
| General-purpose photonic coprocessors are being commercialized by
| multiple companies that have shown interest in supporting mining
| hardware. Stay tuned for announcements.
|
| 10. Is the oPoW algorithm limited to optical devices? If not,
| will there be miners on the system using digital hardware?
|
| oPoW is reverse compatible with CPUs, GPUs, and ASICs.
|
| 11. Is oPoW less secure than SHA256?
|
| oPoW is based on Heavy Hash, a construction that includes SHA3
| and inherits all of its security properties. (see Towards Optical
| Proof of Work above for a cryptographic analysis).
|
| [1] https://www.powx.org/opow
|
| [2] HeavyHash: https://github.com/PoWx-Org/obtc-
| miner/tree/master/algo/heav...
| user-the-name wrote:
| > 2. What other costs would replace energy?
|
| > Hardware depreciation
|
| In other words, instead of massive environmental damage through
| energy production, we would have massive environmental damage
| through e-waste.
| dr_dshiv wrote:
| Yeah, but maybe this drives the development of radically more
| efficient computing, a technology that compounds in value
| over time.
| user-the-name wrote:
| You think nobody wanted efficient computing before this?
| zozbot234 wrote:
| > Cost of entering oPoW hardware manufacturing will be much
| lower due to Silicon Photonics using old CMOS nodes (~90 or 220
| nm vs. ~7 nm for transistors).
|
| If silicon photonics using old process nodes is so competitive,
| cheap to manufacture and power-efficient, why aren't they
| planning to use it for general purpose workloads? Matrix-vector
| multiplication is a key operation for most GPU compute,
| including for machine learning. They say "...On the other hand,
| to be competitive in the field of machine learning, one needs
| to compute billions of multiply-accumulate operations per
| second" but that kind of scale out applies just as much to
| crypto mining, and is the part that's supposedly addressed by
| reusing old process nodes.
| rjmunro wrote:
| > Cost of entering oPoW hardware manufacturing will be much
| lower
|
| That just means more mining hardware will be manufactured and
| used. They might use less energy to run each one, but that
| likely to be balanced out by the energy costs of manufacture
| and the e-waste. More mining hardware will mean the difficulty
| will be increased by the system.
|
| If a Bitcoin is worth $40,000, a miner somewhere will be
| prepared to spend approaching $40,000 to mine it. That money
| will be spent on a combination of buying the hardware and
| energy for running the hardware.
|
| Any reduction in energy use or hardware costs will just mean
| the $40,000 will stretch further, meaning more e-waste and/or
| more energy use, and an adjustment in difficulty by the
| network.
| api wrote:
| One of the limited upsides I see with the cryptocurrency bubble
| is that it's funded some progress in ASICs, and if it funded
| progress in photonics that would actually be quite awesome.
|
| Another upside is that it's funded a ton of very interesting
| cryptography research like SNARKs/STARKs and homomorphic
| encryption.
| jlokier wrote:
| Heh. I worked on a type of photonic PoW in 2019 (but it wasn't
| silicon photonics).
|
| - It's faster and lower power for the hash rate. It's worth it.
| But not as fast and low power as hoped.
|
| - It's a great advantage for the early adopter who can mine that
| bit faster than everyone else for a short time. That was the
| motivation for the project.
|
| - Contrary to the title of the article, making hashing faster for
| less energy doesn't "help with the high energy consumption of the
| crypto currency mining activities" once the technology becomes
| available to enough miners.
|
| It's the same as the introduction of ASICs before it: only a
| _temporary_ advantage to those few who have it first. Of course
| that 's only a few miners, so it doesn't affect energy
| consumption of the whole blockchain much. As soon as a new
| technology becomes widespread enough to have a significant effect
| on the whole blockchain, blockchain proof-of-work returns to
| _exactly the same_ amount of energy consumption as whatever
| technology came before it.
|
| It's because of how the mining-price system works, proof-of-work
| energy consumption is independent of the technology widely used.
| In other words, you _can 't_ solve the proof-of-work energy
| consumption problem with a new proof-of-work hashing technology.
|
| So whenever you see a headline or article promoting a new proof-
| of-work solution on the grounds that it will reduce energy
| consumption of the blockchain - that's false. Snake oil, even.
|
| (On the other hand, other mining methods such as _proof-of-stake_
| do reduce blockchain energy consumption for real, in exchange for
| different problems, perhaps.)
|
| But I think the Eindhoven people have understood this, and it's
| the journalism that misleads in this respect. From the article:
|
| > From our perspective, the ideal proof of work algorithm would
| be an algorithm that spends no energy, but time (i.e. pure
| delay). This kind of proof of work is hardly possible in the real
| world. So instead, we would love to see some sort of a
| "computational delay" when only a small fraction of energy is
| spent on proof-of-work computation, while this computation itself
| introduces a time-delay. We believe that photonics can help us to
| achieve such a "computational delay".
|
| I'm surprised Verifiable Delay Functions (VDFs) are not
| mentioned. There is has been an emerging field of cryptography
| focused on delays enforced mathematically, called Verifiable
| Delay Functions, since about 2018. Rather like the technology
| race of proof-of-work, VDFs rely on the assumption that
| underlying technology (logic gates, arithmetic units (like in
| analogue photonics), etc) is somewhat evenly distributed; that
| nobody has access to a technology that can perform the
| calculations with _much_ lower delay than everyone else.
|
| VDFs still won't reduce energy consumption if they are used as
| another form of proof-of-work. For example if running many delay
| functions calculated in parallel gives a mining advantage, many
| will be built and together they will use the same amount of
| energy as proof-of-work. To provide a real energy consumption
| benefit, the blockchain consensus method needs to change as well.
| Think "proof-of-verifiable-delay". As far as I know, no such
| method has been worked out yet.
| manytree wrote:
| One of the most successful implementations of VDFs in crypto
| right now is Chia, which uses proof of storage space
| interleaved with proofs of time from VDF servers. There is not
| an incentive created by the consensus algorithm to have many
| VDF servers, since only the fastest VDF server participates in
| block creation.
|
| Also, it alters the PoW economics somewhat by utilizing
| already-existing general purpose hardware (storage) and has an
| implementation which does not yet seem susceptible to special
| purpose hardware attacks (i.e., increasing storage density /
| decreasing TCO already has a huge bounty)
| mistrial9 wrote:
| > proof-of-work energy consumption is independent of the
| technology widely used
|
| citation
| nwiswell wrote:
| > It's because of how the mining-price system works, proof-of-
| work energy consumption is independent of the technology widely
| used. In other words, you can't solve the proof-of-work energy
| consumption problem with a new proof-of-work hashing
| technology.
|
| This is not strictly true. The cost to mine will converge with
| the proceeds of that mining -- that is economic law. But the
| total cost of mining is actually the cost of ownership + the
| cost of operation of the hardware. As we know, electricity
| presently dominates the cost of operation and the total cost.
| But you can imagine a very low power chip that is expensive to
| make -- like this photonic PoW, maybe -- and then the cost of
| the chips themselves dominate the total cost and drive down
| energy usage as a portion of the whole pie.
| reginold wrote:
| Appreciate your thoughtful explanation and context. The
| shortcut on "whenever you see a headline about low energy PoW"
| is useful, I had been wondering about that.
|
| One thought - has there been anything on something like "Proof
| of Capability of Work"? ie "Yes, I have all this compute power
| potential, but I'm not using it".
|
| Oh shit did I just back into what you mean by VDF? Basically
| Proof of Sitting Around? I'm gonna hit submit before talking
| myself in circles.
| MinorTom wrote:
| > "Proof of Capability of Work"
|
| I'm not an expert on this, but:
|
| Practicality aside this is either still really wasteful
| (lot's of unused compute sitting around in some datacenter)
| or really susceptible to attacks (e.g. "proof of the
| capability to rent a lot of AWS servers for a few seconds -
| everybody can do that, and somebody will")
| reginold wrote:
| Wasteful: Unused compute sitting around in some datacenter
| is on the first order less wasteful than having it using
| tons of electricity to run a random puzzle. Less
| electricity usage. However, the second order effects may
| negate the effect i.e. miners instead buy up more units,
| which puts more pressure on manufacturing, which ends up
| using that extra electricity, and the energy waste is
| equal.
|
| Attacks: that's exactly what you would need to build a tool
| for. You need to prove that you sit around, and not just
| promising to sit around. It's a tough problem! Proof of Not
| Work.
| jlokier wrote:
| > Oh shit did I just back into...
|
| No, actually you didn't.
|
| > has there been anything on something like "Proof of
| Capability of Work"? ie "Yes, I have all this compute power
| potential, but I'm not using it".
|
| As far as I know, there has not. But I hope you are a
| physicist, because this idea is genius.
|
| The key role played by _counterfactuals_ in quantum
| mechanical systems might make it technically possible to
| prove potential to perform computation that is never
| performed.
| reginold wrote:
| Hmm interesting! I'm a cat, not a physicist though.
| sonoffett wrote:
| As an aside, the algorand layer-1 chain uses VDFs to select a
| validating set per block, weighting member selection by how
| much crypto each account owns. They call it Pure Proof of
| Stake. It definitely reduces the energy consumption and
| increases network throughput, of course with trade offs. See:
|
| https://www.algorand.com/technology/research-innovation/rese...
| tomhunters wrote:
| This is a great approach. You can see how they're going to change
| crypto mining through their interview Q&As. I'm just hoping that
| they will properly execute the plan.
| Mdubrov wrote:
| You can play with mining heavyhash (the underlying algorithm for
| photonic mining discussed in the story) on your cpu/gpu here
|
| https://pool.obtc.me/home
| dvh wrote:
| Green light is 200nm, but we are already approaching 2nm with
| electronics, wouldn't that make any equivalent light CPU 100x
| larger/slower?
| automatic6131 wrote:
| This has two false assumptions, one being that the process
| number (a marketing number chiefly), has any physical meaing.
| And another that you can compare it to the wave length of
| light. And also green light is 500-560nm.
| mmmBacon wrote:
| Why would shorter wavelength light make computation faster?
| Silicon is a great absorber below about 1000nm so infrared
| wavelengths are used. 200nm is ultraviolet.
| poulpy123 wrote:
| Larger, yes, slower no since it uses light as a transmission
| and not electrons
| e2le wrote:
| Wouldn't it be possible to run multiple concurrent processes on
| the same CPU using many different wavelengths of light?
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