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I’d reply to this, but I’m really busy doing dot products on big piles of vectors… they’re really big vectors…
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Computationally, I don’t think they’re that big. Typical vision models have matrix multiplications that are quite small (on the order of 1000x1000 matrices for the huge ones) relative to the problems solved for computational chemistry (a couple of orders of magnitude bigger).
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I’m doing it by hand, and I’m not good at math.
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https://en.m.wikipedia.org/wiki/PPAD_(complexity) This was posted on hacker news a while back and someone mentioned that finding Nash equilibrium is equivalent and that is known NP hard
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nickpsecurity
2 months ago
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The mathcoins: decentralised cryptocurrency, without the blockchain?
A big part of your post is how these protocols don’t even run or survive network conditions. In the centralized model, one of my favorites was FoundationDB. The testing section shows their development process was so rigorous that the guy who runs Jepsen testing on databases didn’t bother testing it since he’d be throwing less at it. In this recent presentation, one of our Lobsters applies similarly rigorous approaches in their work with memory-safe language on top of it.
In comparison, these math coins often look like they’re not even trying. The activities I described found lots of failures in distributed software with benign components. Many more can happen when some parties are malicious intelligently crafting bad inputs. What’s their excuse for decentralized stuff not being as rigorous by default as centralized stuff like I cited? I doubt they’ll have a good one.
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When these huge and glaring problems are raised, most of the counterargument is “number go up”. Certainly that’s what the IOTA cult comes out with, in between the harassment and legal threats.
The big promise is doing the Bitcoin magical flying unicorn pony tricks without wasting an Ireland of electricity. This feels to me like there’s gotta be some sort of no free lunch effect in play, though I wouldn’t claim to be able to prove it.
At least a non-zero number of these guys are more or less sane. They might be wrong or do something dumb, but at least it’ll be an informed wrong.
I was in polite mode for this post, but mathcoin white papers should mostly be read as mad scientist villain monologues. “They said I was mad - but I’LL SHOW THEM ALL!!” edit: actually, I’ll just go add that!
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RE the no free lunch:
For RaiBlocks, the trade-off is that it’s so decentralized that you can’t have a full view of the state of the universe.
Each user has its own blockchain, so you only need blockchains related to transactions that interest you. (Transactions are movements between blockchain, starting with a genesis chain that everyone knows about)
Basically the system works in partial information, but that means that the system will only be partially visibile depending on where you stand
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Empirical fault tolerance testing (as used for simpler and totally solved problems like in your examples) is insufficient for analyzing malicious party actions. Unfortunately, though, no one has come up with a clean mathematical framework for capturing all the intricacies of the economics of the system, so the math is still pretty ugly.
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Empirical testing in that model is just about seeing if any inputs can throw off specified behavior. One tool among many but pretty good at finding problems.
In the traditional models, the builders ensure actions are traceable and revocable with boundary conditions or sanity checks built into the system. Then, they monitor for abuse. They block or reverse what they detect. This system works pretty well in practice. Pieces of the underlying methods have been formally verified as well. The math might be ugly for blockchain-based methods but not for the core of traditional models with decentralized checking and incident response. It’s why I favor designing around the latter.
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No amount of empirical testing is convincing if the mathematical model is not sound. In central authority systems the math is quite straightforward and the testing reveals implementation inefficiencies and bugs. In new and complex trustless systems the math is still pretty suspect, so care and effort need to be spent there instead. This is why the two look very different at the moment.
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Again, Im saying empirical testing can find problems in protocols or other software, not that it should replace math. Also, that it finds problems the math might not find. It can also be used to test math or its instantiation, though.
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bwasti
2 months ago
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Ledger Language Design: Designing and Deploying Formally Verified Public Ledgers
It seems that the formal verification against attackers is limited to cryptographic primitives. This does not seem to encompass the family of attacks possible on cryptocurrencies related to economic control (an example being a 51% attack).
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bwasti
3 months ago
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Bitcoin’s stupendous power waste is green, apparently — bad excuses for Proof-of-Work
I’m always curious about the intended audience with these types of posts. The posts typically paint a straw man picture that there are people unwilling to change the operating model to be more efficient given the option, which is absurd. Should we abandon bitcoin? Is that the thesis here?
Clearly the non technical people would probably not know PoW is inefficient but they also have little to no control over the dominance of bitcoin and the way it works. There are strong economic incentives for actors supporting the current structure to keep supporting it as is and the blog post does not address this problem at all.
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The cryptocurrency posts themselves paint a strawman that we cant do anything better than corrupt, for-profit, centralized tech unless we switch over to blockchains. That’s a lie with many counterexamples. Bitcoin itself also has huge hype and drawbacks in practice.
The author is highlighting that hype and drawbacks. He’s also highlighting a social phenomenon where many proponents try to talk like bad things are good things to downplay them. I’d straight up call that fraud since they’re trying to get people’s money.
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I understand that you have a strong opinion on the subject but you’re essentially calling anyone who has an interest in decentralized systems a fraudster. I think it’s disingenuous to say “people who have interests different from my own are by definition fraudsters”.
Decentralized, trustless systems have important applications. Bitcoin was created as a response to the banks being involved in widespread fraud. Calling Bitcoin users frauds seems to miss the point in the largest way possible.
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“ Bitcoin was created as a response to the banks being involved in widespread fraud.”
So were credit unions and non-profits in response to earlier fraud. I don’t see a lot of them involved in things like 2008 crises. I thought even Bitcoin had a non-profit/foundation controlling or supporting it.
He’s also highlighting a social phenomenon where many proponents try to talk like bad things are good things to downplay them. I’d straight up call that fraud since they’re trying to get people’s money.
That was the key circumstance that I brought up fraud on. The need to use as much energy as Ireland to avoid unscupulous parties screwing up a few transactions a second is one such implication. It’s a total lie since the regular, banking system prevents or catches lots of stuff like that on a daily basis. From there, I pointed out in another comment that a system using regular databases and protocols with distributed checking might take a $5 VPS or one server per participant. Those don’t take the energy of Ireland, insanely-slow transactions, or crypto magic.
That the very-smart proponents of Bitcoin don’t investigate such options or tell their potential investors of such alternatives with their risk/reward tradeoffs means they’re more like zealots or con artists. I mean, most people might trust such alternatives since they’re using the regular financial system. They might love solutions that knock out all the real problems they’ve dealt with efficiently plus make plenty of headway on the more rare or hypothetical risks many cryptocurrency proponents worry about all night.
Save the best for last. If it’s Bitcoin, they might also want to know it’s primarily a volatile, financial instrument used for speculation instead of a stable currency they can depend on as its proponents are selling it. I know people who are day trading these things right now riding the hype waves profitably while the adopters driving them and sustaining the systems aren’t getting the much better thing people probably promised them. Many of them have also lost money they wouldn’t have lost storing currency in traditional, financial system. Looks like fraud to me.
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The need to use as much energy as Ireland to avoid unscupulous parties screwing up a few transactions a second is one such implication. It’s a total lie since the regular, banking system prevents or catches lots of stuff like that on a daily basis. From there, I pointed out in another comment that a system using regular databases and protocols with distributed checking might take a $5 VPS or one server per participant. Those don’t take the energy of Ireland, insanely-slow transactions, or crypto magic.
It sounds like you might endorse the notion that PayPal is more effective than Bitcoin. PayPal supports more transactions per second, catches a lot of fraud, supports chargebacks when fraud does happen, and doesn’t require proof-of-work – it all runs safely on PayPal’s verified servers. This is all true, and for many people PayPal is fine enough.
However, the centralized nature of PayPal does have some problems. There’s always the risk of getting your account frozen, which has happened to countless people. Minecraft made too much money in 2010. Wikileaks pissed off powerful entities in 2012. Google has over 600,000 results for “paypal accounts frozen”. I hear that PayPal freezes lots of crowdfunding efforts in particular.
What it comes down to is trust. If you can trust the corporate entity PayPal to expedite your transactions and send you on your way, then the status quo is fine. But if you have a problem with PayPal, or PayPal has a problem with you, then you need to find an alternative.
You can see the same problem on a larger scale with the SWIFT network. Nearly every international interbank transfer takes place on SWIFT, and it works fine as long as everyone trusts each other. But if you find yourself on the wrong end of US sanctions, suddenly your banking system comes to a screeching halt. Russia, China, and Iran are all too aware of this problem and are trying to build alternatives. Russia is working on SFPS and China is building CIPS. They’re also both stockpiling gold; another asset that won’t freeze you out at a moment’s notice.
Bitcoin never freezes anyone out of their funds. If you have the private key, you control the bitcoin wallet, period. It’s math, not bureaucracy.
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“This is all true, and for many people PayPal is fine enough.” “However, the centralized nature of PayPal does have some problems”
You’re almost there. The centralized solution like PayPal works really well except in well-known failure modes. SWIFT is another good example I bring up myself in these discussions as better than Bitcoin so far. There’s centralized companies, esp credit unions or nonprofits, that aren’t doing all the shady stuff PayPal does. That’s by design. There’s cooperatives leaner than Swift, too. So, the logical, first thing to explore is how to mix those protections with centralized companies like PayPal. If we do decentralized, the first thing to explore should be proven tech for centralized case with distributed checking maybe at a granularity of participating organization like with banks and SWIFT. So, so, so much more efficient to do that.
Instead, cryptocurrency proponents paint a false dilemma between for-profit, greedy banks vs distributed, energy-sucking, blockchain system. It’s misleading given all the designs in between. Not to mention they seem to only focus on what for-profit, scumbag banks do instead of what centralized organizations designed for public benefit can do. A little weird to sidestep the whole concept of nonprofit, consumer-focused banks or companies, eh? It’s like they want a specific solution ahead of time looking for justifications for it instead of exploring the vast solution space trying to find what works best for most peoples’ goals.
“Bitcoin never freezes anyone out of their funds. If you have the private key, you control the bitcoin wallet, period. It’s math, not bureaucracy.”
You’re telling me Bitcoin ledgers, exchanges, and/or hardware can’t be blocked or made a felony in a country. I doubt that. Hell, the mining situation makes it look more like a traditional oligopoly. I can’t remember if they’re all in China or not. That would be even worse given it would be an oligopoly whose companies are under control of one government that’s not about libertarianism and greater good. There’s currently more diverse control and subversion difficulty in traditional, banking system right now if not doing business with banks that are scumbags. I’d avoid any of them on the bailout list to start with.
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Good points all around. On second thought, what you’re describing sounds less like PayPal and more like Ripple.
In May 2011, [the creators of Ripple] began developing a digital currency system in which transactions were verified by consensus among members of the network, rather than by the mining process used by bitcoin, which relies on blockchain ledgers. This new version of the Ripple system was therefore designed to eliminate bitcoin’s reliance on centralized exchanges, use less electricity than bitcoin, and perform transactions much more quickly than bitcoin.
It’s targeting the interbank/SWIFT space, and purports to “do for payments what SMTP did for email”.
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Oh yeah, I loved their concept when I looked into this stuff. Interledger was my favorite concept but Ripple stood out, too. Obviously, I have some technical disagreements but they’re going in much smarter direction. Their marketing said you can pay for stuff with quick settlements, multiple parties checking stuff, and none of Bitcoin’s energy problems. The quick settlements in a global system probably being the main, selling point for most customers.
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there are people unwilling to change the operating model to be more efficient given the option, which is absurd
There are absolutely lots of these people unwilling to change the operating model to be more efficient given the option. This is why I looked for claims from reasonably noteworthy bitcoiners and not random nobodies - though the random nobodies use the same arguments, and quote the noteworthy arguments - and linked and quoted them at length to make it clear that this is not straw but actual arguments they make in real life. This is all real. I’m not sure how I could make that clearer.
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I don’t see a quote about choosing PoW over efficient alternatives. All the claims quoted in your post all seem to be something along the lines of “the benefits of proof of work are worth it.” To these claims you respond with the argument that they are “highly questionable to anyone who isn’t already a Bitcoin fan.”
From my read I’d say you do not address the claim that immutability and a shared transaction concensus is useful with any sort of reasoning or argumentation, just a slew of examples meant to bring doubt in the readers mind. You use terms like “waste” to describe the use of energy, which clearly reveals the a priori and entirely unargued assumption that it is not worth it. A better approach would be to lay down a reasonable framework for analysis and explain the limits of immutability and the price being paid for it within that framework.
Ultimately, I still don’t quite understand the thesis of this post. Why should the externality of energy expenditure be regulated by the economics driving it (proponents of PoW blockchains) and not governments?
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went ahead and wrote it up in python to play with https://github.com/bwasti/avalanche_playground
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There exists an interesting cryptographic solution to this that doesn’t rely on third party randomness (which can usually be manipulated).
The variant more commonly used is phrased as “Coin Tossing Over the Telephone” and here’s a write-up of a solution that relies on the discrete log assumption (this breaks in quantum world): http://www.cs.cmu.edu/%7Eryanw/crypto/lec14.pdf
There’s always going to be faulty argumentation and statistical reasoning is the new trend. That doesn’t meant there’s something better about deductive reasoning, it’s just easier for most folks to validate. I’m guessing that statistical literacy will increase with time.
good point, deductive reasoning is not per-se better. But with statistical literacy, in many everyday situations where empirical arguments are made, the answer will more likely be: We need more experiments. And those are often expensive and time-consuming.