A Warning Against Using Taint

[Bitcoin Oz]

GREAT IDEA.

I find it highly ironic that the forum's "libertarians" are the ones that are most opposed to a personal blacklist. By public ridicule, and by threatening to attack the block chain, they seek to impose their academic hypothesis of fungibility on all bitcoin users. Why do you think you are allowed to use force to prevent me from implementing some scheme on my own client?

This begs the question as to the true motivation of the anti-taint thugs. Why are they attracted to the bitcoin cryptocurrency? Because it makes sense to them personally, or because they are confidence artists and believe the irrevocable nature of transactions will help them defraud more people?

We have a perfect record of every transaction that has ever occured in the economy. Why not use it?

I encourage the sympathetic readers of this post to stop thinking about bitcoin as "cash" and start thinking in terms of a distributed file system containing a perfect accounting ledger. The idea is much more sophisticated than "cash" and will lead one day to a system that will allow us to keep track of our debts to each other in terms of personal economic value.

If you need to ask what a persons morals are before you trade with them you've already lost. May as well use cash which doesnt care that drug dealers or other "criminals" have stolen it from a bank at some point in the past

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[hazek]

GREAT IDEA.

I find it highly ironic that the forum's "libertarians" are the ones that are most opposed to a personal blacklist. By public ridicule, and by threatening to attack the block chain, they seek to impose their academic hypothesis of fungibility on all bitcoin users. Why do you think you are allowed to use force to prevent me from implementing some scheme on my own client?

What force? Please, think before you speak.

You are perfectly free to implement what the OP suggested and fork the blockchain but on the other hand if you should manage to introduce these rules into the current client, we who disagree are perfectly free to fork the blockchain and then we can see who's going to be more popular and successful of which this thread gives you a nice little hint for. And there's no force involved in any of this.

[beckspace]

If I had such scheme in my client I'd use it to see if I received some coins from that famous pizzas (numismatic value).

And, since the possibility is already there, yes, out of curiosity, I'd keep track of the famous heists too.

I'd keep track of how old my coins really are, if they are freshly mined etc.

Don't need a fork to do this.

The true is that bitcoins are not fungible like metals (Jules Rimet Trophy melted down by thieves in Rio de Janeiro - 1983), and it's easier to track than cash.

[Bitcoin Oz]

GREAT IDEA.

I find it highly ironic that the forum's "libertarians" are the ones that are most opposed to a personal blacklist. By public ridicule, and by threatening to attack the block chain, they seek to impose their academic hypothesis of fungibility on all bitcoin users. Why do you think you are allowed to use force to prevent me from implementing some scheme on my own client?

What force? Please, think before you speak.

You are perfectly free to implement what the OP suggested and fork the blockchain but on the other hand if you should manage to introduce these rules into the current client, we who disagree are perfectly free to fork the blockchain and then we can see who's going to be more popular and successful of which this thread gives you a nice little hint for. And there's no force involved in any of this.

I have no problem if its an external white/black list that simply plugs into the client voluntarily like adding an app to your phone or a greasemonkey script for your browser. Any attempt to actually include it in the client or the project is another matter entirely.

[dscotese]

Can someone explain how they'd fork the blockchain?

For all you know, half the people you've traded with in the last month already have a special client with a blacklist/whitelist in it.  How would you identify them so that your client doesn't let them back on the "taint-free" fork of the blockchain?  I think you might have a good answer to this, but it will be one which demonstrates a misunderstanding of the original proposal.

I've received at least one personal request to continue developing this idea from someone who suggested that the information in the blockchain will probably be an important part of the future of private justice.  That is, in fact, why I came up with the idea.

No one has yet pointed out explicitly that if a thief were on this discussion, that thief would make every effort to discourage people from even thinking about the proposal.

"Taint" exists only in the minds of people who think fungible goods can be stamped with some moral seal of approval.

This is an interesting perspective.  I only meant that anyone, regardless how they feel about fungibility, can compile a list of all the address that currently hold coin that was in an address that contained allegedly stolen bitcoins.  So perhaps "taint" is the wrong word for westky to use in describing this fact.

To confuse the issue even more, I have developed a theory (silly, if you want to call it that) that the reason no reward has been offered by the victims of heists is that they weren't really victims:

• A large dealer creates a hidden (fake) member
• The fake member "steals" bitcoin
• The dealer "loses" all the records indicating who they owe.
• The dealer announces that they will reimburse all customers who can prove their claim
• Less than 100% of the customers prove their claims
• The dealer reimburses claims using the stolen bitcoin (after mixing it up enough to avoid suspicion)
• The dealer ends up with some stolen coin that didn't get reimbursed to customers who failed or didn't bother to prove a claim - customers who have abandon bitcoin because it's too insecure.

Anyone can do that if they have the marketing power and the lack of morals.  But they're in danger if we start analyzing the blockchain more closely.

Given the vehemence of the responses to the proposal, I've become ambivalent on the likelihood of this theory.  I asked Gavin for advice in setting up Python so I could enhance his BitcoinTools to do this backtracing, but he hasn't answered.  So, large dealers who are unethical thieves, you might want to pressure him into ignoring me, and perhaps removing the tools lest some other curious soul use them to demonstrate that my theory is true.  I sure hope to hell it isn't.

[Foxpup]

Why do you think you are allowed to use force to prevent me from implementing some scheme on my own client?

Because you can't control who sends you coins. If somebody sends you tainted coins, what are you going to do about it? You can't send them back, since the address they came from may not be under the sender's control (eg, e-wallets), and you can't keep them but refuse to accept them as payment. Can you imagine if that happened with cash? "Sorry, we can't accept this $100 note as payment, you'll have to give us another one. No, you can't have this one back; no, it's not counterfeit, we just think it might have been involved in some form of criminal activity at some point in the past." You'd have some use of force directed at your face if you tried that in real life.

I encourage the sympathetic readers of this post to stop thinking about bitcoin as "cash" and start thinking in terms of a distributed file system containing a perfect accounting ledger. The idea is much more sophisticated than "cash" and will lead one day to a system that will allow us to keep track of our debts to each other in terms of personal economic value.

So, everyone's bitcoins will have a different value to everyone elses? How exactly are you supposed to set prices with such a scheme? "This product costs 10 BTC, but only 8 BTC if the coins come from a verified Mt Gox account, with a 50% surcharge if the coins ever touched SR, plus 10% if they came from a coin mixing service... etc" Is that pretty much how it's supposed to work? And if so, how does that make any sense? That would cause problems if you tried it in real life, too.

[Stephen Gornick]

Can someone explain how they'd fork the blockchain?

Bitcoin is a protocol.  The Bitcoin.org client is code that implements the Bitcoin protocol.  This taint blacklist idea of yours could be implemented in a client without touching the Bitcoin protocol or requiring a hard-fork to the blockchain.    So my reference earlier to a fork was describing alterations to the Bitcoin.org client and not to a fork of the blockchain.   As you also mentioned, you could even implement a taint blacklist that does not require changes to the Bitcoin.org client (e.g., this could easily be done in Armory, for instance, or some other external service.)

So, it's technically very possible for you to do this.  Go do it.  What are you waiting for?  Go nuts!

The reason you haven't is because you know that unless others are using that taint blacklist as well, you doing so unilaterally has no effect.   If you'ld like to boycott tainted coins, you don't need anyone's permission.  You are free to do so.   Isn't Bitcoin and open source fantastic, where you have the liberty to take the software and to basically be allowed to do pretty much whatever you want to with it?

Now if instead you want to change the software that I use, that's when I start to have a problem with you.  Your freedom ends where my nose begins.

[swissmate]

Why starting making the same errors in bitcoins as in the actual currencies?

[hazek]

Why starting making the same errors in bitcoins as in the actual currencies?

Some people are thick that way.. 

[westkybitcoins]

Funny how it always comes back to the same false accusations. Apparently only Bitcoinica and those earnestly trying to track their coins aren't thieves (oh, and Mt. Gox too, for some reason.)

How about you TaintFreeCoin folks go start your own fork? Add whatever makes you feel good about your digital cash being safe from all thefts forever and ever, nevermind the harm to innocents to get it to work. Heck, invite governments in to help out, and they can even guarantee your funds and help you reclaim your lost wallets too!

But I'm never touching that fork. And if it's the main fork that's compromised, whether through protocol changes or social conditioning, I'll be among the first in line to direct funding and effort towards a new cryptocurrency that won't allow for this nonsense. And I know I won't be alone.

Of course, at that point, I'm sure the anti-bitcoin lobby (which is what they are, whether they want to believe it or not) will chase right after us and do what they can to undermine it again. Won't you? <-- *1 BTC says that last question won't ever get an honest answer from any of them.*

"Taint" exists only in the minds of people who think fungible goods can be stamped with some moral seal of approval.

This is an interesting perspective.  I only meant that anyone, regardless how they feel about fungibility, can compile a list of all the address that currently hold coin that was in an address that contained allegedly stolen bitcoins.  So perhaps "taint" is the wrong word for westky to use in describing this fact.

You made it quite clear what you meant. You're the one using the term "taint" to describe it, and as you chose to use it, it's a figment of your imagination just as it would be to declare a pile of gold bars as "tainted" because there are a few atoms (or moles, or micrograms, or ounces, or whatever) in there that came from a shady source. Such a declaration, even if proven true, says NOTHING about the imagined "moral state" of the gold bars, or of the person holding them. And it's nonsense to pretend that shaving off some of the gold and doing something with it changes things.

Again though... go ahead and start implementing your designs. Just don't be shocked when they're ignored by the bulk of the bitcoin community.

[galambo]

Why do you think you are allowed to use force to prevent me from implementing some scheme on my own client?

Because you can't control who sends you coins. If somebody sends you tainted coins, what are you going to do about it? You can't send them back, since the address they came from may not be under the sender's control (eg, e-wallets), and you can't keep them but refuse to accept them as payment. Can you imagine if that happened with cash? "Sorry, we can't accept this $100 note as payment, you'll have to give us another one. No, you can't have this one back; no, it's not counterfeit, we just think it might have been involved in some form of criminal activity at some point in the past." You'd have some use of force directed at your face if you tried that in real life.

You don't have to accept coins that have been obtained dishonestly, either. That would be a personal choice. Because bad actors could respond, to honest traders who only making transactions with other honest people, with violence does not invalidate the idea.

I encourage the sympathetic readers of this post to stop thinking about bitcoin as "cash" and start thinking in terms of a distributed file system containing a perfect accounting ledger. The idea is much more sophisticated than "cash" and will lead one day to a system that will allow us to keep track of our debts to each other in terms of personal economic value.

So, everyone's bitcoins will have a different value to everyone elses? How exactly are you supposed to set prices with such a scheme? "This product costs 10 BTC, but only 8 BTC if the coins come from a verified Mt Gox account, with a 50% surcharge if the coins ever touched SR, plus 10% if they came from a coin mixing service... etc" Is that pretty much how it's supposed to work? And if so, how does that make any sense? That would cause problems if you tried it in real life, too.

What you're asking is like asking how Mt. Gox can give you 5 USD/BTC one day and 6 USD/BTC the next day. Why are exchange rates set on an open market with bids and asks any different than devaluing dishonest money? If someone you want to trade with wants to charge you more because you have dishonest money, you don't have to trade with them. I'd encourage you to find someone to trade with that will give you the full value you believe your BTC is worth.

[galambo]

I do not know of a technical limitation that would require forking the blockchain to implement this idea.

This functionality is built into the bitcoin. Its a fundamental part of bitcoin. I cannot think of a way to remove the possibility of tainted coins from bitcoin without moving to a centralized server like open transactions. If you don't want a taintable currency, run an open transactions server without accounts.

There are people, like deathandtaxes, that have claimed they will respond to a voluntary, per-user, tainted coin system by spamming the blockchain with bogus transactions. I think this shows the level of maturity we are dealing with.

[DeathAndTaxes]

There are people, like deathandtaxes, that have claimed they will respond to a voluntary, per-user, tainted coin system by spamming the blockchain with bogus transactions. I think this shows the level of maturity we are dealing with.

http://en.wikipedia.org/wiki/Nonviolent_resistance

[rjk]

You don't have to accept coins that have been obtained dishonestly, either. That would be a personal choice. Because bad actors could respond, to honest traders who only making transactions with other honest people, with violence does not invalidate the idea.

Did you just skip over what he said above you? I don't know how many times I must repeat myself: it is NOT POSSIBLE to prevent anyone from sending you money, whether "tainted" or not. It just  is  not  possible. It is the way the system was designed from the ground up. Sure you can watch for "taint" yourself, but what are you going to do once it touches you? Return it? Keep it? Donate it?

[Syke]

Since I felt that bitcoin thefts decrease its value, I wanted to make thefts less profitable for the thieves, so I proposed using the taint to accomplish this.

Tainting won't make it less profitable for theives. Just like copy protection, the tainting will only make things difficult for the honest users. Thieves will just work around any tainting you propose.

[cbeast]

This is such a non-issue, but I thought I'd chime in. If you are a vendor and someone wants to spend tainted bitcoin at your store and you refuse them, your competitor probably will not. Bitcoin theft is going to happen. There are numerous ways to prevent it, but some people will not take necessary precautions. This is a good niche for banks to fill. People that want someone else to take care of their security can pay a premium. This premium will cover an insurance policy for any amount that is stolen from you. Your premiums will increase the more you lose. Eventually you better learn to cover your assets or barter eggs.

[julz]

It can work *in a more mainstream setting* - because it's viral in nature, and if your local supermarket subscribes to a particular taint-list, it's in your interests to have wallet software which *understands* the taints that this supermarket subscribes to and the (initially small) penalties(taxes) it is enforced to enact.

Enforced?  By whom?

By the same local authorities which enforce all businesses to be registered and pay their taxes etc.
Bitcoin exchanges and popular high-transaction merchants can be required to implement taint-aware systems by whatever geographical jurisdiction they operate in.

It matters not.  Because it is so easy to mix coins, all you need are enough people willing to throw their 100% untainted coins into the mix and your approach fails miserably.

No - the mixing matters not. It's computationally intensive, but nevertheless practical with today's technology to follow the chain and apply taint in the appropriate percentages.

"There's a time when the operation of the machine becomes so odious—makes you so sick at heart—that you can't take part. You can't even passively take part. And you've got to put your bodies upon the gears and upon the wheels, upon the levers, upon all the apparatus, and you've got to make it stop. And you've got to indicate to the people who run it, to the people who own it, that unless you're free, the machine will be prevented from working at all."
 - Mario Savio

Nice.. but you seem to still be missing the point.
The various 'taint lists' are overlays that will be applied in multiple (usually geographic) jurisdictions. You will always be free to trade Bitcoins as if the taint lists don't exist with other like-minded taint-haters (or because particular taints are largely only enforced in a region you are unlikely to deal with). This isn't about changing the protocol, nor even the reference client.

The effect of various taint-lists being applied is that there will be a viral incentive for the average user to subscribe to them in order to maximize their wealth.
(In terms of being able to freely spend their coins at the various government-audited exchanges & merchants)
Now it's perfectly reasonable to argue that if someone advertises a price in 'BTC' - that this should imply *any* BTC ie a taint-agnostic transaction. I wholeheartedly support that sort of up-front honesty in the arrangement of any Bitcoin deal.

Hows that? Mostly irrelevant.  Tainting will work in a world where the core bitcoin.org software *never* implements any taint-aware code.

Ok, good.  So there will be no code in the client that will try to load your no-fly list.  That's fine then.

Of course. This much should be obvious by now.  
Subscribing to any (of the presumably multitudinous) taint-lists is completely optional - except that there is a clear viral pressure on the average consumer to opt into using taint-aware wallet software in order to avoid
a) penalty-taxes at control points
b) mandatory government reporting on your recent transactions if you happen to be 'early' in the chain of transactions since a particularly attention-worthy event.
(e.g kidnap proceeds, terrorism funding etc)

It'll be locally applied, and thus people will be locally incentivized to have taint-aware wallets - even if they hate the whole idea.

Have you been shopping on Silk Road?

No. Have you?  Are you being facetious here?
Perhaps you don't understand the point that taints can (I predict 'will') be applied if Bitcoin ever becomes seriously mainstream across the globe.

You'll always be free to laugh at the small nation on the other side of the world which implements this, and offer their citizens fewer 'clean' bitcoins from your stash in exchange for Bitcoins that those silly folk view as 'tainted'.   Profit for you! 
(At least until some sort of international cooperation amongst tainting authorities starts to make some of your coins spendable without penalty at fewer merchants)

The only way this sort of system won't work is
a) If some sort of 'blinding' mechanism gets built into the Bitcoin protocol
(see: https://bitcointalk.org/index.php?topic=82947.0   I don't know enough about this to know if it's feasible though)

b) The various taint-implementing authorities go overboard in applying taint - thus so expanding the pool of 'tainted' coins that the black-market economy is effectively stimulated.  (see my earlier comments about it being somewhat self-limiting in this regards)

c) political/social pressure makes tainting impractical for authorities to implement.  
I think this is a fools hope in that some authorities somewhere will implement it anyway. If you can manage to get the law in your country to declare it unconstitutional or unreasonable in some way to 'tax' people via this sort of system - good on you.. but when balanced against law-enforcement's mandate to curtail kidnapping, terrorism etc... good luck!


My preference would lean towards a) but with provisos.
I think your dismissal of the possibility of this sort of viral-tainting even occurring is damaging to the possible consensus required to avoid it in some technical manner.
A counter-argument to implementing a) would be that if law-enforcement truly can't curtail things such as assassination markets and other 'worst of the worst' events, then their only alternative is to crack down in the most draconian ways imaginable to declare Bitcoin utterly illegal and thus limit it forever to the black market.
I suspect that it would be preferable to live with the various self-limiting taint systems and allow Bitcoin to expand to more mainstream usage.

I've not seen anyone else comment on my notion that any authority which over-tainted would effectively be acting against their own interests by increasing the incentive to spend their coins on black-market goods and services.  If this is the case, and I think it is, then a world in which various taints are enforced is preferable to a world in which Bitcoin is equated with terrorism and treated in a zero-tolerance manner by authorities.

Taint systems or not - you'll always be free to transact Bitcoins with others who value them irrespective of taint.
With taint-systems - Bitcoin has a chance of serving more than the black market niche.

[julz]

You don't have to accept coins that have been obtained dishonestly, either. That would be a personal choice. Because bad actors could respond, to honest traders who only making transactions with other honest people, with violence does not invalidate the idea.

Did you just skip over what he said above you? I don't know how many times I must repeat myself: it is NOT POSSIBLE to prevent anyone from sending you money, whether "tainted" or not. It just  is  not  possible. It is the way the system was designed from the ground up. Sure you can watch for "taint" yourself, but what are you going to do once it touches you? Return it? Keep it? Donate it?

It's true you can't stop someone sending you coins that are on somebody's taint-list.
How this is handled would depend somewhat on the particular jurisdiction enforcing the taint.

This is the reason I think any price advertised as simply X BTC - should refer to a taint-unaware price.
If someone using a taint-aware wallet is willing to accept the amount of tainted coins you offer for their product/service - then it's up to them to either ask for the equivalent they will be taxed upon spending it at a control-point, or to wear that cost themselves, or to spend those coins on the black-market or with someone else who values those tainted coins at full value. (The taint-publishing authority is effectively incentivising you to ask for 'clean coins' in the first place)

Of course - nothing will stop you from occasionally receiving coins that weren't tainted when you got them, but are on a taint-list by the time you go to spend them.
I'm arguing that this won't stop some authority implementing this sort of thing.  If your 'tainted' coins aren't particularly 'interesting' because they're later in the transaction tree - they'll just apply some small tax at a control point. If you received those coins from someone closely connected to the event of interest - well you can expect some sort of investigation.

Ugly as it may be philosophically - the software could make it easy for the merchants and average consumer to deal with.
It's all a balancing act that the authorities would have to perform in such a way that they don't overstimulate the black-market, whilst enhancing their capability to gain information about events of particular interest.

When the average Joe is assured that the 'taint' is all about catching child molesters, kidnappers and terrorists - they'll accept such a system, and once a significant proportion of local merchants and consumers are on board with it, the vast majority of consumers will feel unaffected by it.

The ones who are affected, will be those who don't advertise their prices as 'clean BTC'  - hence the virality of the system.

Don't mistake me for a 'fan' of this.  I'm putting forth what I suspect is an inevitability, and examining what it might look like, and how much of a problem it really is.
I'm really on the fence about whether a technical solution in the form of some sort of 'blinding' would be ideal.. or if a minor level of cooperation with authorities in this regard, in order to allow bitcoin to escape to become 'mainstream' is the best outcome.

[justusranvier]

It was hard enough to take this thread seriously before the name change...

[julz]

This is such a non-issue, but I thought I'd chime in. If you are a vendor and someone wants to spend tainted bitcoin at your store and you refuse them, your competitor probably will not.

Only if your competitor is outside of the physical jurisdiction enforcing the taint.
This may however be a good argument against implementing taint in any particular country - as it provides incentive for people to use foreign merchants, thus harming the local economy!

If however, the control-points  are things like supermarkets which have captive local consumers - it's unfortunately not going to be enough to stop it.

Anyway.. the likely implementation would be that the merchant accepts them, but applies the prescribed tax and asks for a further small payment before you walk out of the store.