Hacker News Reader

Comment by Twisell | Hacker News Reader

Doesn't that mean that a whole blockchain could possibly be deemed illegal in some country due to copyright infringement or other liability of publications laws?

I mean if you can't erase the data and keep publishing it, some would say you are liable.

I see that as a particularly twisted legal argument, but couldn't some country use that against blockchain infrastructure if they feel like it?

View on HN

Yes, this is indeed one possible attack vector!

For more information, please see:

https://en.bitcoin.it/wiki/Weaknesses#Illegal_content_in_the...

To quote:

    It is illegal in some countries to possess/distribute certain
    kinds of data. Since arbitrary data can be included in Bitcoin
    transactions, and full Bitcoin nodes must normally have a copy of
    all unspent transactions, this could cause legal
    problems. However, Local node policy generally doesn't permit
    arbitrary data (transactions attempting to embed data re
    non-standard), but steganographic embedding can still be used
    though this generally limits storage to small amounts. Various
    ideas have been proposed to further limit datastorage in the UTXO
    set but are not currently being seriously considered for
    deployment.

All the content on http://dogeyip.com/ is pulled from data encoded into UTXO on the dogecoin blockchain. If you're clever you can encode as much data as you want into any block chain using this technique. Obviously, the techniques used here can also be used on the bitcoin blockchain.

Example: All the text for the blog posts here are pulled via api from data encoded into UTXOs in the dogecoin blockchain: http://dogeyip.com/blog.html

Interesting twist if bitcoin blockchain would be found to distribute illegal porn or private/secret/classified data(it already stores some wikileaks content). # How does government stop/censor a global p2p network? I guess they would put pressure on developers and bitcoin foundation to remove the offending data and update the (official) software to block/reject/deny any upload of it. I assume it would have to employ heavy filtering to prevent rogue actors from spamming illegal content and some functionality to revoke bad blocks(will probably require major changes in ledger code). If there is no change in client software it becomes exponentially harder to censor the data if not impossible: at some point this could be used as legal reason vs anyone hosting the full blockchain. The blockchain would have to be hard-forked to point to the censored version. (I have no idea how this suppose to work since each block depends on previous one: any incident will require to create a new blockchain fork from the start of offending block and this probably won't scale to dedicated attackers inserting illegal content into every block).

That's the beauty of a blockchain (and the rules that dictate how it is written) - one does not simply "remove the offending data".

There are enough different parties involved that acquiring consensus to make historical changes is practically impossible. The data that is there, at least several blocks prior to the current block, is permanent.

An attempt to do this would scare the market, affecting the value of bitcoin. The miners don't want that, so they will act in their greedy self-interest - which means they won't attempt to do such a thing.

Sorry if I'm naive but another thing I've always wondered about that is the exponential size of the blockchain.

I mean if Bitcoin ever gain real traction isn't it pretty inefficient to store all the data and replicate it around? Storage now seem infinite but practicality it is not, won't current blockchain be saturated to the point of uselessness when/if it reach usage level of an actual banking network?

"Let think about scaling later" is maybe not a good idea for a currency implementation...

There's a new block every X minutes. Where's the exponential growth?

I think you're being too literal. I'm not the person you replied to but I've also wondered how the unbounded growth is sustainable.

Moore's Law/Kryder's Law ... advancement in technology outpaces growth.

This is exactly the right mindset to build great software that is totally unable to run on modest hardware.

Only if Moore's law turns out to be false.

A hundred years from now, you could store the blockchain on current day hardware. And that is without talking about improvements in technology.

Well as far as I know X already tend to grow since Bitcoin introduction and it's a big point of discord between developers ("should we increase block size" argument as far as I know).

Now to be more accurate it might rather be a growth according to a logistic curve. Right now Bitcoin is used only by early adopters, but should Bitcoin usage diffuse among general customers it will growth quasi exponentially before plateauing.

Also found out this graph: https://blockchain.info/charts/blocks-size?timespan=all

This is definitely not linear, and keep it mind it's only with a small amount of early adopter that they reached 125 Go mark.

As a matter of comparaison the whole database of the earth map at openstreetmap.org is as of writing only 36 Go fat when delivered in compressed form. https://planet.openstreetmap.org/pbf/

It seems absolutely ridiculous and a waste of ressource to expect that the blockchain shall never/ever use some rotating process to loose weight at some point.

Blockchain like technology can be very usefull, but current implementation look like a very rotten seed. And if a newer version that solve those issue emerge why on earth would they want to give any value to a prototype currency driven by opportunistics "first in" miners?

I desperately hope that no public fund was stupid enough to invest any real life saving to this mess because IMHO it's not a matter of if, but a matter of when it will collapse.

Interestingly, it would be very difficult to censor compressed data that is stored in Bitcoin addresses and impossible to censor encrypted data that is stored there.

> Interesting twist if bitcoin blockchain would be found to distribute illegal porn

I mean... its happened before and you had no idea

Its still in bitcoin's blockchain. There's lots of stuff in there.

Reply on news.ycombinator.com