Is it possible to get the private key from a Bitcoin raw transaction?

ABCbits

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Quote from: Marynarz on June 12, 2020, 02:47:12 PM

Quote from: greenhallo8 on June 08, 2020, 07:38:35 AM

Hello,

Is it possible to get the private key from a Bitcoin raw transaction?

Thank you in advance,

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

You can't obtain private key just from R, S or Z value (which is part of ECDSA used by Bitcoin) alone, otherwise someone will exploit it and Bitcoin will be worthless.
It's different case if you're talking about software vulnerability such as re-use k value, which can be used to extract private key. See https://bitcoin.stackexchange.com/q/35848 for more info.

bob123

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Quote from: Marynarz on June 12, 2020, 04:33:42 PM

Watch with understanding Wink

I don't need to watch it completely.

If your statement is, that it is possible to retrieve a private key from a signed transaction, it simply is wrong.
There is no poorly made YT video which could convince me otherwise.

Marynarz

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Quote from: bob123 on June 12, 2020, 04:13:11 PM

Quote from: Marynarz on June 12, 2020, 02:47:12 PM

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

This completely generic video does not help OP at all.
The answer simply is no.

This video just shows how to retrieve a transaction. It doesn't help OP at all.

Watch with understanding Wink

bob123

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Quote from: Marynarz on June 12, 2020, 02:47:12 PM

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

This completely generic video does not help OP at all.
The answer simply is no.

This video just shows how to retrieve a transaction. It doesn't help OP at all.

Marynarz

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Quote from: greenhallo8 on June 08, 2020, 07:38:35 AM

Hello,

Is it possible to get the private key from a Bitcoin raw transaction?

Thank you in advance,

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

pooya87

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it depends on what you mean by "raw transaction".
the entire bitcoin blockchain that is more than 200 GB is all raw transactions and as others have already said multiple times, you can't get private key from any of them. if you could bitcoin wouldn't have existed!

but if it is a transaction made locally, is unsigned, has other information inside to help signing, created by a weird implementation,... then it is a completely different discussion. for example Electrum unsigned raw transactions contain the master public key. even though you still can't get the private key from that but if a single private key from that wallet is known the master private key (and all other keys) can be computed from that.
or for example there were cases where the implementation was terrible (eg. blockchain.info in the past) and they reused k while signing and that led to easy computation of the private key by just having the signature (the raw tx).

hosseinimr93

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As already stated in previous posts, the private key is not revealed in the raw transaction. So, you may ask how the signature is verified without knowing the private key.

The public key is a function of the private key. So they are related to each other and nodes use the public key (without any need to the private key) to validate the signature.
The transaction you create includes a hash and a signature.
Nodes use the public key and the signature to generate a hash. If the hash generated by nodes matches the hash broadcast by you, they will validate your transaction.

bitmover

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bitcoindata.science

Quote from: bob123 on June 08, 2020, 08:40:31 AM

The private key is used to sign the transaction.

Transactions are being broadcasted into the network. They simply can not contain your private key without the whole system being worthless and broken.

Additionally to what bob123 said, the signature is broadcasted into the network, not the private key.

This is very basic cyber security. THis is why it is safe. Keys are never broadcasted, only the signature which were created by the private keys. The keys never leave the device.

bob123