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Facebook Libra Is Architecturally Unsound

stephendiehl.com

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Re: Facebook Libra Is Architecturally Unsound

#201

Post by swensel »

buboard wrote: post #108
robbya wrote: post #97

Earlier quoted context omitted.

> The plan is to build a ledger that no single party (or coalition of parties in a single legal jurisdiction) has the capacity to edit or alter, and to make such alterations so technically challenging that it's beyond the capacity of any single court or legislature to do so. I'm not seeing why they need a new cryptocurrency for this. If you grow Bitcoin (or any other existing cryptocurrency) to be "too big to fail",…

I think the idea is to have a US-controlled currency before some chinese-controlled currency catches on , particularly in Africa

If the US supported cryptocurrency, particularly Bitcoin, instead of considering regulation, we could keep up with innovation at least, instead of having other countries leave us in the dust in terms of developing the technology.

Re: Facebook Libra Is Architecturally Unsound

#202

Post by carlosdp »

> It is a pivot from a company whose advertising business is so embroiled in scandal and corruption that it has no choice but to try to diversify into payments and credit scoring to survive.

It's amazing to me that nearly every single expert that weighs in on this topic completely misses the intention behind Libra. Facebook wants to make money off of it's massive user gains in the developing world (like hundreds of millions of users massive), but many of those people don't have digital money right now. Libra wants to be their digital money so Facebook can sell more expensive ads.

It's really as simple as that. Move on from the "why" and talk about the rest of it which is the actually problematic part.

Re: Facebook Libra Is Architecturally Unsound

#203

Post by ragona »

pron wrote: post #146
ouid wrote: post #126

Earlier quoted context omitted.

I disagree. You're making two different arguments. The first is that PLT does not study suitability, but then you switch course and say that math analagously can define suitability for specific tasks but suitability is not (and this is my own words) a normed space. Programming language theory does not, in fact, make value judgments, but it does make statements upon which value judgments can be built given context , w…

I think you've misread my comment. Also, of course theory could be used to make judgment given all the necessary context, but the context, in this case, is much harder to obtain than the theory. If we knew whether a language's type system being sound is greatly positive (for some metric), slightly positive, neutral, slightly negative or greatly negative, then the knowledge that a certain language is sound or not coul…

I’m new to this space so I’m not sure how PLT is distinct from formal verification, but my view of it is that formal methods are another form of testing. Unit testing also does not guarantee that you’re testing the right things, but it’s a good way to catch issues post-compile but pre-release. Formal verification moves that so that you catch issues as part of the compilation step, which is just another tool in the general toolbox of finding errors before you ship them to your users. It’s not about proving that your spec is good, it’s about automatically generating tests that find certain types of bugs.

Re: Facebook Libra Is Architecturally Unsound

#204

Post by syrrim »

matthewdgreen wrote: post #56

I don't disagree with the article per se, but I think many technologists are missing the forest for the trees when it comes to the motivations here. Or perhaps they're being charitable and are evaluating Libra on purely on its stated motivations rather than the ulterior motive that Libra can't name out loud. For example, take this quote: "The possibility that a Libra node run by Mastercard or Andressen Horrowitz woul…

There was this story from a month ago:

https://news.ycombinator.com/item?id=21120956

A street vendor in canada was selling cuban coffee. They used "square canada" as a payment processor. Square canada, in turn, used the US bank JPMorgan as a back end. JPMorgan is required to enforce an embargo on money going into cuba. The seller and all the buyers were in canada, but because the money passed through a US bank, they vendor was locked out of thousands of dollars.

We live in a more globally connected world. That should not mean that everyone is (potentially) subject to every nation's laws. It also should not mean that no one is subject to any nation's laws. But enforcing the laws at boundaries seems a whole lot better than enforcing it at every checkpoint along the way. I will not, for example, get out of paying taxes because I received all my money over a blockchain. The sky won't fall.

Re: Facebook Libra Is Architecturally Unsound

#205

Post by __MatrixMan__ »

jayd16 wrote: post #133
__MatrixMan__ wrote: post #43

Earlier quoted context omitted.

What are you talking about? Fiat currency isn't reprogrammable--how would you implement a consumer protection mechanism on it? Pick your favorite consumer protection mechanism, and I'll pick my favorite cryptocurrency and let's compare: A) the up front implemention cost of the protection mechanism in fiat currency B) the up front implemention cost of the protection mechanism in the crypto C) the year-over-year cost i…

>I bet A and C are going to be in the hundreds of millions, if not billions, while B is going to be in the tens of millions and D is going to be in the thousands of dollars. Bitcoin is incredibly wasteful. If we're talking about digital transactions we already have credit cards and digital transfers. A block chain isn't required for those benefits. Supply chain tracking is interesting but literally no one is talking…

I expect the waste of Bitcoin will not carry forward into its successors. Nobody has yet proven that high value proof of stake currencies can scale, but I bet they will.

Also, what kind of consumer protections would you want to see in a currency? It seems to me that ensuring that you actually got what you paid for pretty much sums it up but I'm probably overlooking something.

Re: Facebook Libra Is Architecturally Unsound

#207

Post by pckhoi »

jrochkind1 wrote: post #174

> The possibility that a Libra node run by Mastercard or Andressen Horrowitz would suddenly start running malicious code is such a bizarre scenario to plan for and is better solved by simply enforcing protocol integrity and through non-technical (i.e. legal) means. Hmm, I'm not sure I'm convinced. While "Mastercard as an entity turns into a malicious actor" doesn't seem like an important threat model, it seems to me…

The author didn't say that we should trust MasterCard but he was saying that this trust issue can be solved much more efficiently via the legal system. And in practice the current system already works as billions entrust their financial transactions in these institutions.

Some people have the tendency to think that technology could solve anything and should be allowed to solve everything. This Libra thing is no better than the crypto-currencies.

Re: Facebook Libra Is Architecturally Unsound

#208

Post by cimtrae »

This whole article sounded like he started with a conclusion and then found reasons to support it. It doesn't look objective. I am no supporter of Libra but increasingly media and influencers are about starting with a belief/conclusion based on their bias and then finding proofs for it. Perhaps that's how any human mind works!?

Re: Facebook Libra Is Architecturally Unsound

#209

Post by _nhynes »

amluto wrote: post #165

I have only studied Move by reading the whitepaper, but there's a gaping architectural hole that I found in five minutes: public withdraw_from_sender(amount:u64): Coin { let transaction_sender_address: address = GetTxnSenderAddress(); ... } Checking the global txn sender address is not a sound way to authorize a transaction in a smart contract language. Consider that a buggy or malicious function in a different smart…

It sounds like what you're describing is passing a capability to withdraw balance (which is implicitly captured in an erc20's internal state via `approve` [0]). Of course, cap handling is probably a bit unwieldy for a snippet in a whitepaper, so they're likely making the assumption of "don't call untrusted code." I don't see a construction for sender delegation, so at least it reduces the TCB to the immediate callee.

[0] https://eips.ethereum.org/EIPS/eip-20

Re: Facebook Libra Is Architecturally Unsound

#210

Post by glofish »

leg100 wrote: post #112
glofish wrote: post #90

Earlier quoted context omitted.

The answer is simple - trivial even. As I mentioned before a dollar today should be worth more than a dollar next year since, if you are smart, you can make that dollar work for you for a whole year. Hence the inflation.

No, not "hence the inflation". You have not explained why; you've explained why you think we should have inflation. And why someone thinks something should be is a long way from explaining why something is.

But I did.

The same amount will be worth less in the future! That's really all there is to it. A certain amount of money is not value, money is a number that has a value associated with it, that value will continuously change depending on what you can do with it.

Inflation (deflation) simply reflect the change in value for doing something today versus tomorrow. When the economy works well you have inflation, when the economy works badly it becomes deflation.

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