Bitcoin Forum

I recently read a document entitled "Dissociative Blockchain Code".

There is talk of the fact that the blockchain was not initially designed to recognize the code that would have manipulated it.
While the code that manipulates the blockchain contains within it the genesis block of the blockchain, so the code knows the blockchain.
But if the blockchain does not know its code, it is possible that it can be manipulated by a code that does not conform to the one officially released!

Is it a correct reading of reality or is there something wrong?

Blockchain doesn't have any code, it is more like a database although not quite because it is "raw data". Then there is a code that uses this data.
Since the start has to be the same for everyone and block 0 (aka genesis block) is a special block, it is hard-coded as part of the consensus rules of that cryptocurrency.

As for manipulating the blockchain, it is not possible because of the cryptography that was used.
For example in bitcoin each block is mined by spending computing power and blocks are chained together by each block having a reference to the previous block's hash (hence creating a chain) using a strong hash algorithm. So if even a single bit in any block changes the chain breaks from that block.

Peers who are participating in this decentralized network by running a full node ensure its security and the fact that the consensus rules (defined by the code you are talking about) can't change without them first accepting those changes ensures that these rules remain intact or only changed when majority of the network accept the change.

There is no "official" release when we are talking about a decentralized system. There are only certain rules that everyone agrees on and there is a reference implementation of those rules.
The blockchain is also not released with the code, the chain is downloaded and validated by the nodes from other peers.

Again there is no official/unofficial software in a decentralized system. Also all projects are and must be 100% open source or they have no place in this world. And when they are open source anyone can review the code and see what it does. If there is anything they don't like they simply won't run that software.

You are right, nobody can prevent you from doing that but also you can not force others to follow you either. So it is very simple actually, by introducing the malicious change you have effectively isolated yourself. In other words you have created an altcoin that nobody who wants "bitcoin" would follow.

Lets use an actual example.
Lets say you decide to modify block 696,200 (an existing block) for example change a transaction in it. My node that doesn't have this block connects to your node and requests it, but as soon as the modified block is received by my node (running the correct code) that block is rejected. If you continue feeding bad blocks, my node will ban your IP address for malicious behavior.

Now lets say you change a consensus rule, like increasing the block weight to 10 MB (it is currently 4 MB) and then mine a new block that is 10 MB. Again the same scenario as above occurs. As soon as my node (or any other bitcoin node) receives this block that breaks the consensus rules it will be rejected and your IP address will be banned for being an altcoin.

P.S. Keep in mind that anything that is not part of the consensus rule (eg. using RFC6979 when signing transactions, using BIP39 for the wallet, how the blockchain is stored on disk, ...) can be changed without a problem.

Not at all. The code doesn't expect at all the actions be "uniform and certified". That's why the code contains consensus rules.
Since the others have the proper code, their code will simply reject your block if it didn't follow the rules.

This means that whatever malicious you do, it will either remain local if you altered the consensus rules, either it will be dropped too when the correct blockchain will become longer than yours.
Keep in mind that you cannot really alter older blocks...

You seem to be speaking of "the blockchain"™... as if there is only a singular instance of it which a malicious actor can alter and thereby affect everyone.

In reality, any malicious actor will be able to do whatever they like to their copy of the blockchain data... with whatever code they want to use. However, as illustrated by pooya87 illustrated, any "non valid" data created by this malicious actor will be rejected by everyone else running "non modified" nodes.


Also, you keep talking about manipulating the blockchain... the data is not manipulated... it is "created" (ie. transactions are created, blocks are mined)... the entire concept of the blockchain rests on the fact that it is immutable... so the data cannot be "manipulated".

So, I am thinking I am not understanding what you actually mean when you say:

In what ways is "the blockchain" being manipulated? ???

It's basic software engineering.

This is similar to any other large-scale program using a versioned file format for storage. Search index "databases" (mostly just sqlite files or some proprietary "lite" database as a file) for example, usually have a version written at the top of the file and the indexing program is coded to understand versions up to a specific one.

But newer file versions running on older software are oftentimes incompatible because they often remove fields read by the older versions. You don't see this happening with Bitcoin Core though, because developers update the local block[chain] database format versions in such a way that they are backward-compatible with older client versions by never removing any fields.

So it all depends on the program whether the developers are careless and don't make backward-compatible changes to file formats. If this is true then the older programs will flat-out fail when they encounter a newer format (this includes third-party "new" formats that are unknown to the public for the purposes of this post).

A backward-compatible change will cause older programs to continue to work normally, including in the face of these private, unknown new versions.

So we're talking about arbitrary blockchain software now, not Bitcoin Core.

The thing about those is that many of them have a weakness in that they are not properly audited as well as they should be for a digital currency consensus enforcer. This is usually due to a lack of manpower and resources (they'd rather audit bigger projects. These projects usually have small download sites making it easy for some random person with their own modifications to masquerade as the official download site.


That would be better for most of those one-release, never work on upgrading again kind of cryptocurrencies.

I skimmed the "paper" that describes this and it seems like the idea is to add a virtual machine, and the bytecode that handles the blockchain validation itself is embedded in the blocks. This leaves me with a major question.

Who decides what updates to the bytecode should be added?

Anyone with the power to push updates to the bytecode (and therefore changing how ALL blockchain nodes process data, instantly) has tremendous power over the network, making it basically a centralized network.

In contrast, in the current Bitcoin ecosystem, any node operator is free to run any code they want, and refuse updates they disagree with. This could result in forks, as with BCH, but I see this as a feature and not a flaw - the Bitcoin core devs do not have absolute power to decide what code runs the network.


Remember how the DAO code (equivalent to your "ABC" blockchain's bytecode) running on Ethereum was flawed, and it allowed hackers to take over everything? What stops a similar scenario from happening with an "ABC" blockchain?

No, blocks contain just raw data, you can see who owns what, but it can be executed in any way, using any Turing-complete language you want. It has to be compatible with the rest of the network, that's the only required thing to reach consensus.

There is no official "bytecode", you just have some data in the chain and that data can be accepted or rejected by your node. If you ask about the format of the data in the chain, then all users running full nodes. You can release new version, but you have to convince people to install that version to bring your changes into reality. If developers will start doing some things that people don't like, then they can always switch to another coin (or simply stick with the old version).

For some coins, the blockchain is identical to some point in time, that's probably the easiest way to see that there is no single version matching the blockchain. Also, many miners use their own custom software (and hardware) to mine blocks more efficiently, using "generatetoaddress" will work, but using specially optimized software is better.

I don't agree with that. If the blockchain is disconnected from the binary code, it can be updated and changed easier than if it is connected, because you don't have to stick to some processor architecture or some programming language. Also, if you have self-upgradeable blockchain, then you can force some unwanted update just by pushing some data into the chain. That gives too much power for miners and changes them into semi-developers by letting them auto-update other nodes, which can be dangerous. Even versions released by Core are not auto-upgradeable, you have to upgrade it yourself.

I'm not talking about Bitcoin, I'm talking about the stupid "associative blockchain code" idea the original poster is pushing, which explicitly wants to have validation code in the blocks themselves: https://medium.com/@mocciaro.smz/associative-blockchain-code-f84f385c45ec

To me, the only way a bad-actor node could even possibly inject a corrupted block into the chain is:
a) submit a corrupted block it claims has been solved to the network.
b) have a confirmation of the corrupted block because a pool (or one helluva private solo farm) used SPV mining and so did not check that it is a valid block with results that matches the inputs to it.
c) have that first 'confirmation' validated by several other SPV nodes in a row lengthening the now corrupted chain.

With 'c' therein lies the biggest hurdle: By The Book a block is not considered 100% validated until it has 101 confirmations by the network. IF at any time a node that properly validates the block data tags it as invalid it can and most likely WILL be kicked out the the blockchain and treated as the start of an invalid fork. More than enough nodes do that and even the pools like Poolin, ViaBTC, etc that are known for pushing empty (SPV) blocks do do full block validations often enough to catch bad-actors.

OK, I kind of get your idea. But usually, when someone makes a consensus change to the Bitcoin client that affects how they create blocks, transactions, etc, the honest nodes are programmed to reject these items of data. This makes the rebelling node orphaned from the rest of the network so the blockchain can't be manipulated from this avenue.

I'm definitely not saying it's not possible but perhaps with more subtle consensus rule changes that don't directly alter the blockchain content the blockchain could be manipulated, but it's usually a researcher that discovers these first and it becomes a CVE.

Apparently the OP and friend think that in all the time Bitcoin has existed no one has tried attacking it in every way possible both in theory and actual attempts? It is a very safe bet that probably hundreds if not thousands of bad actors including no doubt more than a few State-sponsored players have tried and to-date, all failed.

As I said earlier, it is the constant self-checking of results from the massively distributed mining process that ensures corrupt blocks do not make it very far before the bad fork is terminated. It would take a prolonged 51% attack based on the corrupt block(s) lasting through the full 101 block confirmation rule to have any chance of working.

That would very soon be caught by the rest of the network and in one of the rare moments of all the major players acting together - stopped. It has been done a few times before. Just google "billion bitcoin bug" or refer to here for a short description (https://news.bitcoin.com/bitcoin-history-part-10-the-184-billion-btc-bug/) of what happened when someone tried it.

That said, I wonder if there any tools to look at the 'fuzz' of failed blocks/chains that branched off the main chain before being terminated?

Aside from the person, where's a link to the paper itself?


I'm not sure which of the 2 ideas that came into my mind, or none?,  u r referring too:

1- A scenario where a hacker manipulates a Bitcoin Core update for example and more than 51% of full nodes download it; a situation that I think a Cryptographic code checksum or  a Core signature on the update would solve it.

2-A situation where a whole country software is manipulated, which could isolate its Blockchain from the true International one without individuals noticing it; either for a common virus with lack of security measures, or for political reasons an enemy tries to obfuscate population data. In both cases I don't think ur method will help, still Solution 1 of a global code hash/integrity only "may" help
(I'm talking hypothetical here, I mean if there data on a global Blockchain they can retrieve the last Internationally saved copy, but if the fact is discovered after some time they will lose some data and have to get back to the last integrity verified point)

Sorry, that's kind of frightening &  I'm not sure if it's related to the white paper u r talking about.

There is nothing in the "paper" about this - all it says about updates to the code is "Other blocks of code can be seen as applications on the solid blockchain, as well as updates of the genesis code."

Can you please quote the part of the white paper that explains how code updates are approved and included in the chain?

This is about the Connection Layer Protocol (CLP).

Sorry is the author banned from the bitcointalk group (or a certain section or a certain moderator),
or the paper itself is banned from the internet???
How is that?

I reject any such frobidding of ideas/info/knowledge

I tried to Google search it out of curiosity, only found this about Dissociative Social media platforms,
https://bettermarketing.pub/social-media-is-dissociative-ac1b3c67b5d3
But it didn't upload either

The link to the "paper" was mentioned in an earlier post:

---

This seems fundamentally flawed... the Genesis block is just a data block... it's not a "code".

So, it seems their entire premise rests on this really bad interpretation of what a "genesis" block is? ???

They probably looked at some "how to create an altcoin" guide and saw that in the bitcoin core source code there is a method (https://github.com/bitcoin/bitcoin/blob/e9d6eb1b8071805cec1cc4e1352a13a7adc55ca8/src/chainparams.cpp#L51) that creates the Genesis block (which shitcoin creators change) and built this whole nonsense "article" on top of that. But the fact that there is a method generating the Genesis block instead of a hex being decoded doesn't change the fact that block #0 IS hard-coded or the fact that in the decentralized network people running the "correct" code are generating the correct Genesis block and it doesn't matter what a malicious node does.

The midium link doesn't upload in my browser.
Anyway, why didn't u tell this explaination to the author & clarify any ambiguity he/she has instead of banning them?


Still one question from me (I'm an academic person who have never run a full node) why the Genesis block is "generated" and not downloaded as part of the IBD Initial Block Download process?

Could it be that u mis-spelled the word the author meant & it is "assortative"?
In the paper
https://appliednetsci.springeropen.com/articles/10.1007/s41109-019-0249-6

The authors state the result:

Where they define the term

But here the authors do not state that as a problem, they just clarify a difference between cryptocurrencies  & social media transaction graphs

So, in essence, someone has conceptualised a blockchain that can't be forked, but only has an unproven theory about it.  And they think we're going to unban their account so we can hear more about something which Bitcoin can't possibly benefit from.  Yeah, sounds likely.   ::)

It is not exactly generated, in a way the Genesis block is hard-coded because the method always returns the same thing on all systems at all times.
The genesis block is hard-coded because everyone has to start from the same origin, otherwise if a node wanted to start downloading from block 0 the other nodes could give them another completely different chain (like an altcoin's chain with the same consensus rules as bitcoin) that could even be longer than bitcoin's with more work and that node wouldn't have any way of knowing it is on an altcoin chain.

While I agree that it should be hard-coded, I disagree for the reason you've said. A node should always follow what's having the most work. An altcoin could be using Bitcoin's genesis block and still have more work than Bitcoin. Does a hard-coded value determine what chain will a node follow? Obviously the one with the most work.

You probably confused it with “longest chain” or “different chain”.

Couldn't this be simply achieved by having a Cryptographic hash or finger print of the authorized code released by Bitcoin Core?

Isn't this the same simple problem of how do u know the update/SW you  are downloading is not a malicious tampered version?  
.
And for
I do not know the person, but as a matter of principle
I'm against banning from a public group for dispute reasons, unless there is a serious violation of the group rules just don't read or comment on his/her posts.

These discussion boards are supposed to be for sharing ideas, discussing & brainstorming, clarifying any misunderstanding, answering & helping beginners,...etc

There was a violation of rules, repeatedly. This board is about Bitcoin. All OP has to say about Bitcoin is that its genesis block is flawed for some made-up reason that doesn't make any sense, and doesn't offer any plausible solution for it anyway.

This is not a beginners board either. Time to stop feeding the ban-evading troll.

I don't understand why a special block, why not just verify a cryptographic function on the code before running it?

Honestly, the fact that I couldn't find the paper elsewhere, the medium link doesn't work, the one person acting as if a lawyer to the author hardly posts very small parts, not a name/twitter/....etc
All of these make me suspecious.

Express it & discuss it yes, but a full development I'm not sure; at least not on the publicly used software ... you don't run trial experiments on people or their savings.

As an example, my idea about UTXOS categorization/partition ( their Merkle as a start) although best suited to be tested on Utreexo, but I can not force them too.
Yes I expected them to do it or at least discuss with me why don't they think it's promising, but for the sake of scientific research or achieving more improvement; not for me as a person.
Like I'm discussing here without knowing this SMZ or even anyone of you.

This is apparently the document OP is talking about which is also written by SMZ: https://medium.com/@mocciaro.smz/associative-blockchain-code-f84f385c45ec (to be fair, it would've been easier on all of us if you just linked this in the first place though)

And also to be fair, the author constructed his arguments well, and looks like he did his research.

I'm not going to comment on this whole "ban" situation (create your own thread for that if that's important to any of you) since it's not relevant here, but it reinforces my view that this is mainly a theoretical idea and that actual code to apply this theory will need to be produced later at some point.

He's claiming that he can make an unforkable blockchain and doesn't address even the most basic issues with that, for example what would prevent creating a fork that doesn't include his magic hypothetical code, or what to do if the centralized provider of the "correct" code gets taken over by someone like CSW. It doesn't look like any serious thought was put into this at all, it's a fantasy "solution" to a non-existent problem and even if it was possible, it would create more and bigger problems.

See what you made me do, I'm feeding the troll again. Ew.

What forces u to participate in the discussion?
Are you the moderator the who banned him?

Maybe try this archive.is link: https://archive.is/V2nyU

Hopefully that will load in your browser (which browser are you using? ???)


I am not familiar with the account that is supposedly banned... or the reasons for them being banned, but I doubt it has anything to do with this "whitepaper". More likely it was for repeated breaking of forum rules (https://bitcointalk.org/index.php?topic=703657.0). I certainly didn't ban anybody (I'm not a mod/admin).


When you start a blockchain... where are you going to download the Genesis block from if you're the first node? ??? ;)

The simple solution is to simply generate the genesis block and hardcode it... anyone (ie. any node) that wants to use your blockchain is going to need to use the same genesis block. It really makes no difference if it is generated or downloaded.

But as an interesting thought... I wonder if it would be possible to create a Bitcoin client that attempts to "download" Block #0? Is it even possible for a current Bitcoin Node to send Block #0? ???

Of course, if you were to attempt to download Block #0, how do you know that it is the "real" Block #0 and you haven't downloaded a fake one from a malicious node? ??? Hence, hardcoding it in the client is the only logical option.

Thank u, I will save it & read it soon to decide. As a first thought, I'm thinking a Cryptographic finger print of the code could solve the problem; do not run the code before verifying it.


This phrase was directed to the comment preceding it, not you.
For he/she said or complained from having to re- explain & defend his rejection to the paper and the author again & again

You mean like the signed sha256sum's of the installers/zip files... signed by the public key of the Bitcoin Core devs? As available on the download page: https://bitcoincore.org/en/download/

The problem is... Bitcoin Core is not the only node software available or able to connect to the network and process transactions and blocks etc. Anyone is free to create their own node software. It seems that the author wants there to be only one node application or something... as that is the only way that I can think of that the "blockchain could know the code". ::)

Otherwise, the blockchain would need to know about any and every node application ever written... and then what happens if someone tries to create a new node client tomorrow? Well, the blockchain would reject it because it has "no knowledge" of this code. ::)


That's fine... I didn't think you were personally accusing me or anything :)

I was just pointing out, that I've never heard of this S.M.Z. person and had no knowledge of their ban... but that people generally don't get banned just for wanting to discuss ideas etc.