Topic: Can someone explain me PK in Sig but not on Blockchain (Read 249 times)

When we talk about wallets, the more common terms you will come across is custodial and non-custodial. The exchanges you mentioned are custodial. They have custody of your coins and own the private keys. You only have a notion of control given to you through an account that you access with an email/username and password. But the coins are theirs. Non-custodial is the exact opposite. The service/software you use doesn't have custody or control of the keys, you do.

Centralized and decentralized is something different. Centralized refers to usually a single point of failure. For instance, if Binance's website gets hacked or taken down, you won't have access to your account any more. Because their single point of failure just failed. An exchange like Bisq, on the other hand, is decentralized. It doesn't have a central server somewhere that must store a copy of the software. Hundreds or thousands of people run unique copies on their computers and connect to each other P2P. The disappearance of 1, 5, or 50 computers doesn't result in any downtime because the peers that are online can still trade normally. And if I wanted to take Bisq down, I would have to prevent every single computer in the world to run the software. With the Binance example from above, we only need to make the website disappear. 

Quantum computers are creating not only to working out Bitcoin private keys and it is not main utility of those computers.

I think development and creation of more powerful computers will require more foundations from technological developments as well as costs spent to set up those computers. It requires more inputs than what developers have to do to upgrade Bitcoin protocol and algorithm to be safe from Quantum computers. Developing things with code is more easily and less challenging with things need to have physical things and rely so much on available physical equipment development and resources.

Nobody expects quantum computers to be able to break cryptography by brute forcing 256 bit keys, which is what this picture demonstrates. We expect them to reverse public key to private in a non-exponential time (as with classic computers now), by algorithms like Shor's. Quantum computers breaking cryptography is not a FUD, it is just resolvable. Once the development of quantum computers has risen so much that working out private keys can be done in practice within a reasonable time frame, we will have long switched to a quantum-safe algorithm.

Just as was said in the video above, not your keys; not your coins. If an exchange controls the keys to your assets, they can block you from withdrawing it, they can also lock you out of your assets if they get any request to do so from law enforcement agencies. Mind you that you do not control the wallet address given to you by a centralized exchange, they are the ones that control it.

It is not possible for anyone to block Bitcoin addresses, if you have an address on an exchange and you were prevented from spending it, the address was not blocked per se, the 'owners of the keys' (that's the exchange) do not just want you to spend it and you can't spend Bitcoins without the valid keys; thus don't hodl your assets in exchanges, but move them into your non-custodial wallet.

I found it, it was a YT video, and it was not the Developers, sorry my wrong, it was about Coinbase and Co., that are not decentralized.
My main thinking was not the upper 10k holders, that maybe know how and what in ( coldwallet ... ) to store your BTC, the mass was what i think about, they are using Coinbase, Binance, Etoro ... and if your Coins are there,
they are not decentralized.

https://www.youtube.com/watch?v=YGwaV9wk_V4

Sorry for my wrong writing, of what i meant.

You haven't heard wrong, you are just confused about what it meant. Here is an example of a topic that is basically covering the same thing that you had probably seen: https://bitcointalksearch.org/topic/updated-psa-most-stablecoins-can-be-frozen-even-in-your-own-wallets-5204055

Let me put it this way, did you know the banks can close your account or freeze your money? Why? Because they are centralized.
It is the same with cryptocurrencies, if they are centralized they can do that and more. Sometimes they are not 100% centralized so the degree of control they have is different. In short the more centralized they are, the more control they will have over the system.

As an example of a fully centralized cryptocurrency you can check out most of stablecoins like Tether aka USDT. They can freeze your coins if they wanted to.
Other parts you mentioned earlier and I highlighted in your previous comment can happen in centralized altcoins, like reversing your transactions or blocks by the "company" like what happened in centralized shitcoin known as Ethereum.

None of it can happen in bitcoin though. Simply because bitcoin is decentralized.

There are many discussions about risk from quantum computers as well as fud to make people fearful about it.

Let's take a look that this graphics.


How hard is it to brute force a Bitcoin private key
Bitcoin seed security analysis

Hi, how are you? Sorry but i don't get what is your actual doubt about this.

Can you develop a little more what is your doubt?

If you want a little algorithm of how a Signature can proof that you own a private key you can read more or less this article:

ECDSA: Elliptic Curve Signatures

Basic points of this are:


Basically The proof is S and the Message you should be able to reproduce the same R value that is in the signature.

Still have not found the thing to mark some ones Reply, and show in my answer post. Maybe somebody can send me PM how to do it.

I will look in my Bookmarks, to find the article i read about the blocking addresses thing, belive me it's not a "I hear it from ... " it's "I read it in a article".

And the thing with AI, i use AI everyday private and Job side, and no matter how you be pro or contra, or how my people say in my Region ContraRegule, it's not how the AI answer, it's how you ask it.
Everybody who work with AI has the same story, "When i begin to change my questions, format my Questions in another way, the answer was pure fantastic!"

You can be the fastest badass typing Guru, and know how a script or code should look, in your imagination and your ideas. But when you ask a good AI ( not the free ChatGPT ), and put all your imagination and your ideas in as a task for the AI, follow the path of not forget things or not asking all you want, in the right order, the script will be generated in not half time of your time, in a 10th time.
And that is the danger i see in the upcoming extreme fast growing of AI's.

And never forget a good AI don't need to search for errors in your script hours or days, type in the error and the AI will search for a solution, and if this solution is also wrong, it will go on searching, searching and searching.

I am not a friend of AI, i see it as a humanity danger, not for us OLD people, i see it as a danger for our kids generation.

And it will not be the time of Quantum Computing, when Crypto will be hacked, it will be, when the AI's have enough "Digital Brainpower", we are in genesis phase of AI, what will come nobody knows.

This is also a challenge I have though about, the pace at which AI is growing and being updated automatically, we might get to a point where these set of Quantum computing technology might be able to fathom what we never imagined will be possible to deduce.

Maybe I'll put this as a topic for a more comprehensive chat, but what happens if we get to the point where AI can read off a PK from ECDSA, even if we are made to understand that its oneway and irreversible through the transaction hash.

You seem to be confusing bitcoin with some crappy stable coin?

Blockchains is the universal name for the system behind cryptocurrencies but each one uses a different algorithm which gives different levels of decentralization and security. There are some blockchains which are run by someone with central servers from which they can freeze transactions at will, but this cannot happen with bitcoin cause of how it is designed.

- Jay -

Cryptography was invented thousands of years ago and from its first day none of the algorithms were supposed to remain strong and useful forever. They always have a lifespan. Nothing has changed today with Bitcoin and the cryptography used in it or any other place we use cryptography today like this very website you are visiting through SSL encryption.

Instead of reading the nonsense some crappy AI gives you maybe you should try reading reliable sources like the bitcoin wiki or the bitcoin book, etc. so that you don't end up with wrong information (the bold parts) which you think are "facts"!

The:

• private key is used to create signatures.
• public key is used to verify signatures.

I presume you're talking about the latter.

That is correct. When you make a transaction, you most likely share a signature and a public key for nodes to verify it. ("most likely", because you can spend bitcoin without using private keys, public keys and signatures, such as these)

The AI poses no threat to breaking Bitcoin's cryptography.

It seems that you don't know how bitcoin works. There is no centralized server and there is no admin. There are thousands of nodes all around of the world. They have a copy of the blockchain, validate transactions and make the network decentralized.

What do you mean by the "know everything"?
Bitcoin code is public and all transactions are also available to the public. There's no one who has access to information that is not available to the public.


That's not possible. There's no one who has control over transactions.
Miners are free to include any valid transaction they want and there's nothing stopping them from doing that.

Take note that bitcoin code is available to the public and there's nothing hidden from us.

First thx for reply to this topic, sure all what you write is on his place. The Enigma thing is more as a factor, to show never giving up.

We have a time of more and more AI, and thinking "Out of the BOX", is now maybe more important that some time ago.

Forgive me if i am wrong, but the only answer you become in fact of Bitcoin Security was and is, "The time will change, when the Quantum Computering will be able to Brute all PK's" and this is far away.

My first thought approach was, when i came over a Paper of Filippo Valsorda (and i know the method is old and don't work anymore), why nobody see the Danger in the AI's,

and the possibilities that exist, to let them do the complexity of math and scriptwriting, because we all should know, we can have a big knowledge ... but the AI has a Bigger one.

Try to ask a AI, and you will be astonished, about answers that a normal one of us, know or never will know ... but the answers exist.

I hope you understand what i mean, because the 2 points in my first post, are answers of a big AI, and i don't go further asking. I like more to disscuse with you here.

And to the decentralised thing ... The Blockchain is run by someone (maybe you will reply no its a peer-to-peer system ...), that's a fact, and the fact that the Admin of the Servers know everything is also a fact.

For example ... how is it possible that the developers can take action, in transaction from Stolen Wallets, they can mark them, and the transaction will never be approved by the Blockchain.

Thats no theory, that's a fact and it was done in the past. I am no enemy of BTC, i handle it, i hodle it, and i work with it, but i also like to ask, what could be.

Blockchain is a neutral storage of some organized pieces of data, meaning that it will consume almost anything you feed it, regardless of authenticity or validity. If it were an independently living thing located in an isolated environment, we wouldn't need all these guys, influencers, and organizations running full-node software that actually verifies everything occurring within the decentralized network and passes information to other participants. Yes, you are right that private keys are never shared with others, but nodes verifying these signatures do not need that information anyway. To verify a piece of information referred to as a digital signature, you only need a signature itself, an address, or a public key and message. No private keys are involved in that process of verification.

This is a little misleading, the enigma works in some kind of Security through Obscurity think in enigma like a close Source Encryption algorithm this algorithm wasn't reviewed by the community.

On the other hand all the steps in bitcoin have been reviewed by the community and have strong approval of it.

It's true that ECDSA has no proof of its complexity,  but if you review it you may notice that all the information of the private Key is lost in the process of Double and add (Scalar multiplication)

So basically you are comparing oranges and apples.

Not to mention all other steps in the address creation, sha256 and rmd160, all of them one way functions.

• With your private key (PK) you create a digital signature and you reveal the public key. Every node can then verify that the signature is valid for the revealed public key without the need to expose the matching private key. It is very likely that an unique private key has an unique public key and that there are no collisions.
• The blockchain doesn't verify anything. Bitcoin nodes do the verification based on consensus rules baked into software. The blockchain concatinates blocks of transactions. The blockchain doesn't even know about public addresses because those aren't stored in the blockchain either.

Whenever we make a bitcoin transaction, we don't broadcast our private key at all. We create a digital signature using our private key for each of the UTXOs we want to spend. The private key can't be derived from the digital signature.

No. To verify the transaction has been created using the correct private key, the private key itself isn't required.
People can use your digital signature to verify you own the private key without you need to reveal your private key.


For more details on how the digital signature is verified, you can read the following article on learnmeabitcoin.com.
Digital Signatures (Signing & Verifying)

In simple term, the bitcoin uses ECDSA. The digital signature is actually created by private key and the verification is done by public key. This way the public key proves your argument ownership without having to expose your private key. So with this method just anybody cannot prove owner of your bitcoin without the knowledge of your private key to that public key. Do not worry about the exposure of the public key because it can never be used to get your private key, it is a one way thing.


So during transaction verification the data of transaction hash is created by you and then sign with your private key, this combination is the digital signature. Then moving forward transaction data with the signature is propagated including even the public key, so the public that accompanies it is what make them confirmed that the one who actually sign this transaction is the owner

Found an image that explains it better



source