Topic: Eventually the FUNGIBILITY issue of bitcoin will make headlines ... - page 4. (Read 10581 times)

The most important thing is that there is no blacklisting in the core of the Bitcoin never introduced. What will third party services do and decide to do is their own thing and we can hardly influence their decisions.

About Bitpay blacklisting coins, what else can we add about the morons that just got hacked $2 million of their money via a simple email. No comment really!

I believe that is where we differ. From where I stand fungibility is an inherent property of the monetary system. Subjective valuation and user preference due to a privacy/traceability issue is entirely dependent on "people".

The units themselves are never discriminated against, only their history can be. For example, I could argue that the "taint" is interchangeable given the fungibility of each units ie. I can trivially replace any spent satoshi from a "tainted" output by another one with no distinction made between the two.

This is what fungibility is. We may need to agree to disagree but I insist that any issue you bring up is one of privacy and traceability, not fungibility which is inherent to Bitcoin.


Do you understand then how subjective your definition of fungibility is? From your POV any medium of exchange that is suspect to traceability by any means is non fungible.


I guess except if some sort of social convention discriminates against this particular medium of exchange... right?

Yes fiat institutions.

But I also have to tell you that personally I have avoided dealing with certain private parties (as a BTC buyer) because I felt pretty confident their coins would have really ugly histories and could cause problems for me in the future even though I had no immediate intent to deal with a fiat institution. So I simply took my business elsewhere, with probably some small cost, but it was worth it to me to avoid the risk.

As long as those fiat institutions are major ecosystem participants -- and they are -- their perspective matters, and not just to those dealing with them directly.


When you use words like "will" you come off like an idiot or a religious fanatic. No one has a crystal ball. Things may work out that way, or they may not.

I'm personally far from convinced that Bitcoin (or any present cryptocurrency) "will" have a marketplace of note at all in the future, which further makes such statements rather ridiculous. It's success seems highly speculative.

Privacy and fungiblity are different concepts, but perhaps there is some overlap?  The fact people often conflate them would indicate this.

When individual or groups of satoshis may be (on the basis of unique traits or general taint) identified and discriminated for/against, how is Bitoin "absolutely fungible?"

If Bitcoin is "absolutely fungible" then how did BTCE [do whatever they did] with the Evolution coins?

I see your point about gold (in spite of the tenuous radioactivity example).  (Non-radioactive) gold is fungible, even if a particular institution acts in a particular way towards some particular customer's particular gold.

But wouldn't the gold be be even more (ie exhaustively) fungible if it could somehow negate the ability of any and all institutions to discern its provenance, thereby destroying the possibility of non-interchangeability in all particular instances?



Bitcoin: Absolutely fungible, even when it isn't.  Because No True Bitcoiner.
Monero: Private and unlinkable.  Can't be not-fungible.

BTW, if it was illegal for merchants to accept XMR, we'd just use shapeshift or https://xmr.to/ and be on our fungibility-not-affected way!   

I'm curious who it is these people you refer to are dealing with?

Fiat institutions? That would make sense. Else I can't see how there'd be any important amount of individuals out there carefully examining the provenance of the coins and checking them against any blacklists or what not. I'm not saying it doesn't happen but that seems like a somewhat far-fetched scenario.

I, for one, could not imagine me refusing to business to someone on the basis of the history of the coin he is attempting to pay me with. On a long enough timeline, that can't be good for.. business. More resourceful individuals will show up on the marketplace that won't be bothered by such folklore.

This again is incorrect.

We discussed a few posts back that two satoshis coming out of the same transaction (even if different outputs) are indistinguishable (though only if no social convention develops which would distinguish between outputs of the same transaction, as I explained).

But two satoshis from two different transactions are absolutely distinguishable. The have different histories and therefore can be trivially distinguished. It therefore becomes non-fungible (i.e. non-interchangable) if people choose to attach some significance to that difference. The technology or physical properties do not determine fungibility here, people do.


It certainly would be non-fungible if some important property were recognized to apply to the radioactive gold (for example if it were stolen). People would routinely check gold with a geiger counter before accepting it and you would not be able to substitute your radioactive gold for non-radioactive gold.


Not entirely, but I don't know any other way -- besides obscuring the information that makes outputs usefully distinguishable from each other -- to make the intrinsic properties of the technology demand fungibility rather than relying on a social convention to do it.

Obscuring information on the ledger doesn't in and of itself provide useful privacy or anonymity though. For example, you might be still required to present (physical or electronic) identification whenever you spend coins. You would have essentially zero privacy and anonymity but the coins themselves would still be inherently fungible.


You are not the first to observe that non-transparent ledgers may be banned rather than regulated. That's not unique to Monero though. ZeroCash is apparently coming, Confidential Transactions make the history less meaningful, etc.

Monero could also be subject to arbitrary USG regulations.

Since people are willing to go to such a stretch to come up with scenarios that supposedly undermine's Bitcoin fungibility then how about this:

Merchants are forbidden to accept Monero: since we cannot tell where you money comes from it is not legal and you should use the transparent alternative. "You don't have anything to hide anyway, do you?"

So rather than blacklists certain "tainted" coins they would effectively blacklist the use of an anonymous currency. Now that wouldn't make Monero non fungible would it?

I agree with that, as stated. Clearly if you read the whitepaper or satoshi's early writings it was not intended to pay attention or attach any significance to coin histories (which were viewed as an implementation detail), but people do, and you can't stop them.


This is incorrect. Any counterparty to a transaction can define things any way they like. If someone doesn't like your coins they can choose not to deal with you, or charge you more. It doesn't take a third party to impose such a view. It is purely a social convention how much weight to attach to to the history. If it becomes widespread, then it won't matter what third parties say, because people won't want coins with problematic histories. If history is widely ignored, then obviously it won't matter.

The important point is that nothing about the technology forces people to behave in one manner or the other.


I guess that depends whether you are the one dealing with the "complications" related to people paying attention to coin histories. I know several such people personally. It isn't marginal to them.

FTFY 

I do not disagree that there is a privacy issue and I obviously support any attempts at improving this aspect.

The whole point of my intervention is this thread is that fungibility and privacy are two different concepts that are too often conflated.

Bitcoin, fundamentally, is absolutely fungible. Perfectly so in fact. Two satoshis are exactly alike much like two atoms of gold are indistinguishable and can be perfectly substituted.

I can taint gold and make it somewhat traceable using radioactivity. That doesn't make gold non-fungible but only traceable to a certain extent.

TLDR; When people speak of Bitcoin's fungibility "issue" they really are referring to a privacy/traceability one. 

I don't even have to go there.

My claim is that anyone that uses Bitcoin as it is meant to be should absolutely not be concerned over fungibility.

Understand that these scarecrows are put in place by third parties attempting to restrict your monetary freedom.

I absolutely disagree with your conclusions, outputs are only non fungible in transactions involving third-parties which is not representative of Bitcoin's design.

Moreover it can certainly be argued that these occurrences are marginal and nothing more than distractions.  

Yes, that tweet may have induced my 'there are no tainted Bitcoins, only tainted institutions' epiphany.

I don't like those tainted institutions any more than davout and you do.

But they could not exist if Bitcoin was perfectly fungible.

You'll never get a notice from Poloniex saying "Hey buddy, we don't like the guys you sent your Monero to, so we're closing your account."

Polo doesn't know that; Polo can't know that (because stealth addresses and ring signatures).

A few months ago, I opined that Monero enables defections which Bitcoin cannot.

This conversation has helped begin putting meat on the bones of that claim, as I'm finding the concept of 'perfect' (ie, exhaustive of all use cases) fungibility an interesting distinction from Bitcoin's circular 'good enough, assuming you are already rich, lol' version.

Those "two satoshis" may be indistinguishable, but they are inexorably linked by their common tx.  Hence, the anti-taint cottage industry of mixers and tumblers and shufflers and Darkcoins (lol).  And (more significantly) the booming trade in blockchain analytics.

Let's set aside considerations of fungibility at the recipient level (maybe I'm sending BTC to MPEX, where they don't GAF where my BTC has been).  There is still a privacy-driven fungibility issue for the sender.

IE, a confidential transaction is not, from my sender POV, equal to a public one.  Maybe I don't want my ex-wife/IRS/boss to know where I'm sending BTC.  The public and private tx are not interchangeable, and that's why people pay proportionally extra (directly and in the form of TTP risk) for fresh coins and mixed/joined/tumbled/shuffled ones.

Coins/satoshis/etc. are not uniquely identifiable as you say, although it is possible to define a rule which would do so. For example, I think some of the colored coin schemes use a rule that if you mix colored and non-colored coins, the colored coins come out in a particular sequence (for example, the first input might directly flow to the first output, etc.). An alternative rule, of course, is that mixing colored and uncolored coins simply destroys the coloring. Both can work. Assuming that people are going to observe a similar convention for regular Bitcoins is a bit contrived but not impossible.

Putting that aside, what exists on the blockchain are not coins but outputs, and outputs are uniquely identifiable because each has a unique history. That is very close to the definition of not being fungible, because fungible means equivalent and interchangeable. How people choose to interpret that history is again up to them, but we've seen numerous examples of people doing it, so it is implausible to flat out say that people will close their eyes and pay no attention to that history behind the curtain. Again we have reached the point of a social convention, and it really is not up to you or me (except in our small role as individual society members) to decide what that convention is.

If you want to argue that anyone who tries to implement rules like this will be rendered irrelevant when the crypto singularity comes and fiat fails, and anyone who attempts to pay attention to the unique historical properties of different outputs will be laughed at, then I don't necessarily disagree, but mostly I'll just wait to see you on the other side/moon.

For now we have the reality that outputs are very much not fungible. Some can be safely used with Coinbase/Bitpay/exchanges/etc. and some can not.

This tweet by Davout sums up the situation perfectly

I still don't see how that holds true.

As smooth himself has pointed out, once two satoshis are spent from two different inputs to the same output they are indistinguishable.

It took me a second, but I now appreciate the #bitcoin-assets 'there are no tainted Bitcoins, only tainted institutions' POV.

I love the smugness of that serene maxim, and look forward to the day when it has practical value for those of us with <100 BTC.

OTOH, I believe (smooth will have to back me up with The Science) that Bitcoins are not perfectly fungible at the protocol level because they are uniquely identifiable, and thus may be discriminated against (ie, considered "bad") by individuals, if not in the aggregate.

AFAIK, the Monero protocol couldn't tell "good" coins from "bad" ones even if it wanted to, so its coins are perfectly fungible (no matter what, and without need to invoke rosy assumptions about the future of crypto vs fiat).

Bitcoin Black/Whitelists: technically trivial to implement and enforce, commonly done in status quo (eg stolen Evolution coins at BTCE)

Monero Black/Whitelists: technically impossible to implement or enforce (is it true?)

Good looking out, didn't catch this chart. Still, it is seemingly clear to me that the trend is up.

Consider a rough 30 day average: https://blockchain.info/charts/tx-trade-ratio?timespan=2year&showDataPoints=false&daysAverageString=30&show_header=true&scale=1&address=

Moreover if we consider that this chart also includes chinese exchanges' reported volume that it is reasonable to say that there numbers are considerably skewed in favor of exchanges' volume and that in effect the ratio is likely greater.

In any case my point was that by all account we can put to rest this theory that a "predominance" of Bitcoin's economic activity is affected by potential policy decisions of third parties.

For example: https://blockchain.info/charts/tx-trade-ratio?timespan=all&showDataPoints=false&daysAverageString=1&show_header=true&scale=0&address=

Shows no dramatic change since 2013.

It is not the gross amount that matters, it is the ratio, and especially (since the ratio on its own is largely an uncalibrated number) the change in the ratio.

Where do you get these numbers?

I just did a "gross calculation" and a quick roundup of major exchanges + approximate total of minor ones brings me to about 3,500,000 BTC in volume over the last 30 days. That includes OKCoin's obviously bogus 1,850,000 reported volume.

This chart seems to indicate the blockchain sees an average of 250,000 BTC volume per day. 7,500,000 over 30 days.
https://blockchain.info/charts/estimated-transaction-volume?showDataPoints=false×pan=&show_header=true&daysAverageString=7&scale=0&address=

I think it's clear there's a lot left to be accounted for.