An Analysis of the Impact of Arbitrary Blockchain Content on Bitcoin [pdf]
fc18.ifca.ai
fc18.ifca.ai
This may have a chilling effect on participating in the network, thus reducing the number of nodes, and undermining the trust on the blockchain and in the coin because the reduced requirement of computing power needed to mutate the blockchain.
Accordingly a determined actor with enough resources (e.g. a nation-state) can render the bitcoin value-less and use-less at will....
Exactly. I brought up the same scenario recently.[1]
The top 2 replies to my comment was basically, "unless you're looking for illegal data, it's not a problem."
That head-in-the-sand ignorance completely misses the point. It's not about how _you_ specifically ignore illegal data and therefore, you have absolution of guilt. It's about the whole world's response to bad data in the blockchain.
That, ah, isn't how that works. You can't just dump terabytes into the blockchain for BTC, LTC, or really any blockchain I can think of that has any sort of adoption.
Custom tools can be used to extract any data from almost any other kind of other data, using steganography. You can extract illegal data from innocuous looking tweets, using the right tools.
It's the difference between taking random bits of your computer to assemble illegal content vs taking one specific set of bits and applying mere transforms to then to retrieve illegal content.
For example, I don't think it's a defense for the owner of a website to say "this horrible illegal content I'm sharing is only accessible via a custom tool that downloads and decodes image data from me...such as a web browser."
Your arguments seem to be of the nature of "information is information; you can't suppress it and you can't make it illegal" but that's not really what this discussion is about.
the "key" is a very simple algorithm, that is obviously not illegal
My point is that you could unknowningly store illegal data, without blockchain being involved.
Anyone sharing the data by torrenting an apparently legal file, reposting an image, or quoting a text could redistribute potentially illegal data.
This problem is not constrained to blockchain.
The problem with blockchain is that a full node will be knowingly storing and distributing illegal content (or at least is likely to held to be, once the chain is widely known to be infested with such content.) The only way to.stop is to stop storing and interacting with the chain.
With a torrent, you could be unknowingly doing so, but very easily stop doing so with the particular content once you discovered it (without abandoning torrents altogether), which may or not be a complete bar to liability but would probably result in generally more lenient treatment in any situation other than the government is targeting you and the actual offense is pure pretext, in which case the content hardly matters.
And which subsets of illegal data are legal?
The problem with the blockchain is actually its greatest strength: it's immutable. If somebody reports a block containing child porn there's no way to remove it without compromising the blockchain's integrity.
The number "Pi" contains all hate speech and other illegal content imaginable.
>The number "Pi" contains all hate speech and other illegal content imaginable.
That's irrelevant. If you don't think so try downloading child porn, get caught and argue that "it's just decimals of Pi!". Report back with results.
That's the problem with the blockchain: there is no mechanism for deleting data (well, there's pruning, but that's meant to save storage space after processing all the data).
But apparently this is a practical problem. Phil Pennock wrote on oss-security (http://seclists.org/oss-sec/2017/q4/375):
[...] we've had keyservers in Europe shut down because of privacy demands because an append-only mesh-fill datastore can't remove keys and people send out their email address and name paired into a key and then get upset because it's out there; we're one illicit-material-in-photo-uid incident away from global shutdown.
In theory the miners of a public blockchain could also do such auditing, to simply decide to ignore anything containing child pornography, just as they could arbitrarily decide to ignore any transactions. Of course, it's probably expensive to actually check all possible transaction in this way, and they most likely don't have a big enough incentive to. And of course for other sometimes illegal content (e.g. a picture of Mohammed or a particular nation's state secrets) some group of miners would censor while some wouldn't, and it would only take the miners who don't censor to win once for it to forever fork the blockchain.
On the other hand if you wipe (even partially) Bitcoin's blockchain your basically destroy the currency.
I was just thinking about this a lot this week, actually. The really crazy thing is that, due to the PROTECT Act, a person in Japan could legally upload certain manga that the US would consider CP. So one wouldn't even have to risk jail to poison the blockchain.
Unfortunately, most people are too puritanical to even dare to think about the topic, let alone opens debate it or soften the law.
The law is there to protect children, profit doesn't feature in the calculations.
Normalization of behavior is a worry that always comes up with "immoral" information. Violent movies, violent video games, adult porn, strip clubs, prostitution, open homosexuality, etc. You'd need actual evidence to support the claim that it makes things worse not better or neutral.
could they be persecuted as facilitators of the ilegal distribution?
Recitations in GDPR require systems to be designed with privacy in mind. Immutable structures like the Bitcoin blockchain or Merkle trees in other applications would seem to be fundamentally incompatible with some GDPR privacy requirements.
Let's say Google receives a valid right to be forgotten request for an entry in one of their Certificate Transparency logs? Then what? I don't see how it can be dealt with without destroying the integrity of the log.
But in many cases the whole reason systems use these structures in the first place is so that there's transparency and public verifiability.
And against whom would I claim my rights, for example: my right to be forgotten (Article 17: The data subject shall have the right to obtain from the controller the erasure of personal data concerning him or her without undue delay [...])?
In the case of a distributed blockchain, who is the controller as defined by the GDPR?
And even if one could identify a controller (say, in the case of a blockchain under centralized control), there are still exceptions to the rights of data subjects. Privacy is key to the GDPR, but not an absolute.
What gets more complex is if you put non-business-related "sensitive" personal data in an immutable system, e.g. if you're building an illegal blacklist of union organisers.
There's probably an interesting computer science problem here in how to create a data structure that retains as many advantages as possible from the immutable data structures, but still allows compliance with the GDPR.
I have always wondered this. What will a country do if someone embeds child pornography or a picture of Mohammed or something in the blockchain? Will it then be illegal to store the blockchain in that country? Is a link to such an image much different to an actual image? It seems hard to ever stop this happening with a public permissionless blockchain, pretty much by design.
Which is why child porn is one of the Four Horsemen of the Infocalypse: terrorists, pedophiles, drug dealers, and money launderers.
That we are trying to apply flesh space laws to bits just goes to show how stupid we still are: https://en.wikipedia.org/wiki/Illegal_prime
Until we change the laws we have to meet the needs of digital computers instead of the printing press we will have these ridiculous ways of attacking useful new technology.
This seems a really difficult area that's almost incompatible with the way we do criminal law, because intent and knowledge are so hard to prove either way. Even where there's plenty of circumstantial evidence of intent it is not going to prove it either way.
You could plan to murder somebody for years, leave an evidence trail and then run them over by complete accident. Should that be premeditated murder or manslaughter? In the eyes of a jury it will almost certainly be premeditated murder. You could black out at the wheel and for a while have no knowledge that you have killed. From the philosophical perspective the lines are blurry: Only the individual can actually know, and given the amount to which people can self-delude themselves, even that isn't guaranteed.
Juries do not make decisions on reasonable doubt, and often default to balance of probabilities. Depending on the jurisdiction, when a unanimous verdict cannot be determined a majority one is accepted.
Let's say I have a HDD I write random data to as a block device. What are the implications for me in twenty years if somebody creates an image file format that can decompress some of the linear subregions of my random HDD data. I haven't the time now to do anything but a very simple analysis of this. Intuitively this depends on the size of the drive and the size of the compressed file. Let's say for arguments sake it can encode a prohibited piece of data in 10kB.
At what point of completely random storage material are you likely to have a forbidden piece of data? Well, each terrabyte contains approximately 1e12 such linear subsequences. And we need 1e3010 such subsequences to match a forbidden sequence. So that's 1e2998 or so TB if there is only one forbidden piece of data. With more I think the birthday paradox kicks in. Now if we can encode the forbidden data in 8 bytes or such then we reach the problem much sooner. I doubt that will happen somehow.
In the old days it was unfathomable you could be locked up for something you didn't know was a crime.
This pretty much has never been true, at least in Germany. "Unwissenheit schützt vor Strafe nicht". Even the Roman Law didn't excuse for lack of knowledge https://de.wikipedia.org/wiki/Ignorantia_legis_non_excusat
There are edge cases where you may escape punishment (Verbotsirrtum) but only if it was unavoidable that you erred. Involuntarily distributing child porn may carry lesser punishment, but it will certainly be investigate unless you can assert a privilege such as common carrier status or inability to control the transmission, as for example Tor nodes could.
Not incompatible at all. Most criminal laws actually have a mens rea requirement.
No I am making the very simple case that a number is a number and you can't make a number illegal.
All digital information is numbers and banning any of the 4 horsemen of the infocalypse at mere possession will ensure we retard most useful technologies.
The only time that flesh space laws should apply is when flesh space actions are taken.
An example: terrorist training material is sent on how to build a bomb. Until a bomb is built, or a conspiracy to build a bomb is made, nothing illegal should have happened.
You can obviously have a contract between two people for sending digital information between them.
That this only happens in digital space does not mean the contract can't or shouldn't be enforced.
How can an element or a wster-based solution be illegal?
This is one thing that most of the free world has gotten mostly right: you can say anything you want in writing without having to fear the government.
It needs some corner cases ironed out, obviously, but for the most part you can write whatever you want and not be arrested for it.
But simply having a written text, drawn picture, photograph or a video should never be illegal in itself.
Exactly! However, reality is very sad.
A map could potentially get you in prison in India https://archive.fo/nLtJX
> The draft bill says: “No person shall depict, disseminate, publish or distribute any wrong or false topographic information of India including international boundaries through internet platforms or online services in any electronic or physical form.” The maximum penalty for wrongly depicting the map will be a fine of Rs1bn ($15m) and imprisonment for up to seven years.
If you have naked images of your ex-partner, they don't magically become revenge porn until the moment you share them without permission(at which point it's a crime and it's already punishable by existing laws).
Sharing MP3s? It's just a number.
Sending death threats? Just a number.
Directing relatives to the money drop so they may get their loved one back? Just a number.
Maybe the act in itself wasn't even illegal. But publication may still be. I can have your consent to record, but not to publish. Should we just accept that the publication was illegal, but once-breached, further publication is legal?
So if I want to air something, I publish it anonymously and can then freely refer to it? A lot of laws would have to be rewritten for this to work. Privacy laws and copyright laws among them.
What you lack is a program to decode them consistently (I hope).
You can read digital information in any way you please. An image is fundamentally two numbers that give you the height and width and a bunch of number triplets that give you the color values for the pixels inside. You can always find a transformation from any number to any image given you allow the transformation function to be odd enough.
To put it simply, you sound like this guy: https://www.youtube.com/watch?v=8VB3uQHa14g
When trying to outlaw some numbers in some situations.
Interestingly, it's a distinction that happens to more-or-less match our own intuitions about the situation, which is something interesting to ruminate about a bit.
>an image depicting mild nudity of a young woman. In an online forum this image is claimed to show child pornography, albeit this claim cannot be verified
(I don't know exactly what it would mean to "verify" that an image contains child pornography, since in the US and UK at least some of the relevant laws refer only to what the image "depicts", not to the age of the people used in its manufacture. Either way, the copyrighted content seems enough to establish the illegality of the blockchain in principle.) It seems unlikely that any prosecutions will happen though, because blockchain technology has a lot of mainstream support.
[1] https://steemit.com/ethereum/@titusfrost/ethereum-s-vitalik-...
> Also I would suggest trying EOS which is supposed to wipe out Ethereum and hopefully will. I now fully endorse EOS as an alternative to Ethereum.
> I also wanted to address the slanderous attacks against me stating that I am an "Anti-Semite" which is completely bogus. I criticize Zionists who are at the very top of the New World Order Power structure, just under the Jesuits.
What the fuck did I just read?
I've memed this online and to friends. It doesn't help that one Ethereum Foundation member was celebrating on twitter about how esoteric people are in the EF even saying that there are oculist members.
Not much you can do about it anyway.
In the US at least, I'd hope that we probably wouldn't criminalize 1M people for the actions of 1. Hopefully in other countries they wouldn't do that either.
In this case, you have an idea that child porn is illegal, but you had no idea it was coming through your blockchain.
Those are very different cases.
- You create a special rule for a block known to contain illegal data.
- The illegal data in the block gets NULLed. The other transactions are left untouched.
- The checksum for the next block is no longer calculated, instead it is hardcoded. This means there is no way of verifying the transactions in that block. Perhaps you add a new signature for the block with the NULLed data to make it harder to tamper with.
Once you start doing this workaround once you will probably have to do it repeatedly.
2. The problem is a technical one as a result of a blockchain allowing content other than financial transactions to be a part of the record.
Maybe I am misunderstanding the process.
But there has to he some kind of centralized group that bless the new block. Also, a new client and miner software must be released. Perhaps a new version every time an illegal item is included, or perhaps the program can check the list automatically in a website. In both case, it will break the decentralization.
As with illegal drugs and, in the UK, unlicensed firearms, this means the prosecution doesn't need to prove intent. (Mandatory — usually harsh — sentence terms are usually part of the package with strict liability offenses.)
> Section 160(1) creates an offence for a person to have any indecent photograph or pseudo-photograph of a child in his possession. [...] "Possession" involves both a physical and mental element. [...] The mental element is knowledge. A defendant must knowingly have custody and control of the photographs found on the device in question.
Downloading the blockchain, should it contain such images, would constitute "making", but it subject to similar mental requirements:
> The act of making or taking the indecent photograph or pseudo-photograph must be a deliberate and intentional act, done with the knowledge that the image made is, or is likely to be, an indecent photograph or pseudo-photograph of a child.
I suspect that not knowing that the blockchain does contain such images, not having knowledge of which transactions do, and that it requires specialised decoding rather than just being embedded per se/a default/intended usage would be enough to raise a defence.
https://www.cps.gov.uk/legal-guidance/indecent-images-childr...
"The presumption of mens rea is rebutted by express provision in the statute excluding the requirement of mens rea. Where the statute is silent as to the requirement the general presumption remains, however, the courts may look at other offences created under the same Act. If the other offences expressly require mens rea, the courts may well take the view that the omission to refer to such a requirement was deliberate and that Parliament intended to create an offence of strict liability." [0]
E.g. there is a section on mens rea for the Protection of Children Act 1978 here: https://en.wikipedia.org/wiki/Protection_of_Children_Act_197...
Actually, pardon me for a minute, I have sci-fi short to write :).
(Similarly: possession of an unlicensed gun carries a stiff prison sentence. But if someone chucks a pistol on your lawn and you without delay call the police and ask them to take it away, you're probably safe. Picking it up and taking it inside is another matter, however ...)
The USA is a bit different. District Attorneys being elected means they have an incentive to bring charges against "soft" targets who'll take a plea bargain, i.e. hapless teens and people too poor to afford a decent defense lawyer.
> The defence is made out if the defendant proves that the photograph in question was sent to him without any prior request by him or on his behalf and that he did not keep it for an unreasonable time.
https://www.cps.gov.uk/legal-guidance/indecent-images-childr...
And if you do all of those things, why even bother with the blockchain and all of its cons in the first place? All that remains is the completely accountable surveillance of users, and I believe that becoming a bigger surveillance machine than even Facebook ever was wasn't the original vision for the blockchain.
I think that unless the main blockchain projects such as Bitcoin, Ethereum, and so on, don't start implementing anonymity by default soon, in a few years they won't be allowed to do it anymore.
The tech still remains and still functions, arguments or not.
So who's going to shut a blockchain down? I don't see it happening.
Blockchains primarily enable credible accounting of digital events, e.g., money transfers in cryptocurrencies. However, beyond this original purpose, blockchains also irrevocably record arbitrary data, ranging from short messages to pictures. This does not come without risk for users as each participant has to locally replicate the complete blockchain, particularly including potentially harmful content. We provide the first systematic analysis of the benefits and threats of arbitrary blockchain content. Our analysis shows that certain content, e.g., illegal pornography, can render the mere possession of a blockchain illegal. Based on these insights, we conduct a thorough quantitative and qualitative analysis of unintended content on Bitcoin’s blockchain. Although most data originates from benign extensions to Bitcoin’s protocol, our analysis reveals more than 1600 files on the blockchain, over 99 % of which are texts or images. Among these files there is clearly objectionable content such as links to child pornography, which is distributed to all Bitcoin participants. With our analysis, we thus highlight the importance for future blockchain designs to address the possibility of unintended data insertion and protect blockchain users accordingly.
I see this as a very strong legal attack vector on full nodes and cryptocurrencies, probably a way around it, is to only allow meta information on a cryptographic form, even then the owner can publish the view key publicly.
A drastic solution is to just prune or don't even allow metadata.
How did they come about? Do you have a source for this?
Saying that someone's work is obvious except to idiots doesn't teach anybody anything; it's just striking a pose. Please don't do that here; instead, explain. If you don't have time to explain, you can save yourself even more time by not posting.
But who knows.
As long as you can distinguish between a 0 and 1, or any two states in general, you can store and represent arbitrary data. This basic premise is what makes digital computers so flexible and powerful, and how things like stenography and crypto work.
The MimbleWimble blockchain design [1] on the other hand doesn't leave any room to add freely chosen data, mostly due to the lack of any form of scripts.
CryptoKitties craze slows down transactions on Ethereum
public service advisory: read the whole btc wiki, there's a lot of great stuff in there!
https://en.bitcoin.it/wiki/Agent
https://en.bitcoin.it/wiki/Script
Links of note: https://bitcoinmagazine.com/articles/bootstrapping-a-decentr...
I don't know why the links for agents are relevant.