Topic: BIP39 - Conversion from *PUB Mnemonic(24) to *PUB Mnemonic(25) with passphrase (Read 222 times)
August 25, 2018, 05:23:59 PM
It can't be done. mnemonic -> seed -> xprv is the order of things. mnemonic > seed involves hash functions and the extension is used as a salt to that so it isn't possible to go from seed > mnemonic. in your case you don't even have the binary seed or the xprv. you have the xpub and reversing that to get the xprv would require breaking ecdsa as well.
August 25, 2018, 06:38:10 AM
Hi Bob,
Thanks for taking the time to reply.
For the sake of what I'm trying to do:
I have access to 3 things:
A) YPub - Which I know was created with 24 seed words
B) Another YPub - Which I know was created with 24 seed words and the 25th word
C) The 25th word itself
What I am trying to do, is use the first YPub (A) as well as the 25th word (C) to confirm whether the seed from A and B are the same, without the seed itself.
So without the seed itself, can I determine if A + C = B
Thanks for taking the time to reply.
For the sake of what I'm trying to do:
I have access to 3 things:
A) YPub - Which I know was created with 24 seed words
B) Another YPub - Which I know was created with 24 seed words and the 25th word
C) The 25th word itself
What I am trying to do, is use the first YPub (A) as well as the 25th word (C) to confirm whether the seed from A and B are the same, without the seed itself.
So without the seed itself, can I determine if A + C = B
August 25, 2018, 02:06:52 AM
Is it possible to convert an X/Y/Z-PUB Key without a seed extension to what the X/Y/Z-Pub Key would be for the same seed with a Mnemonic added?
This is only possible through bruteforcing the 25th word to the (known) mnemonic seed.
In other words, without access to the seed, can a Master Public Key be converted to what said Master Public Key would be if a (known) passphrase were added to the seed without knowing the seed itself?
No. Without access to the seed, you can not create a xpub at all.
As far as i understand you, you are worried about the security of the 25th word ?
As long as your seed is kept secret, noone will gain information about your xpub/xpriv/addresses/etc.. The xpub of your seed without the 25th word doesn't make a difference here.
August 24, 2018, 09:16:50 PM
Is it possible to convert an X/Y/Z-PUB Key without a seed extension to what the X/Y/Z-Pub Key would be for the same seed with a Mnemonic added?
In other words, without access to the seed, can a Master Public Key be converted to what said Master Public Key would be if a (known) passphrase were added to the seed without knowing the seed itself?
Edit - For the sake of what I'm trying to do:
I have access to 3 things:
A) YPub - Which I know was created with 24 seed words
B) Another YPub - Which I know was created with 24 seed words and the 25th word
C) The 25th word itself
What I am trying to do, is use the first YPub (A) as well as the 25th word (C) to confirm whether the seed from A and B are the same, without the seed itself.
So without the seed itself, can I determine if A + C = B
In other words, without access to the seed, can a Master Public Key be converted to what said Master Public Key would be if a (known) passphrase were added to the seed without knowing the seed itself?
Edit - For the sake of what I'm trying to do:
I have access to 3 things:
A) YPub - Which I know was created with 24 seed words
B) Another YPub - Which I know was created with 24 seed words and the 25th word
C) The 25th word itself
What I am trying to do, is use the first YPub (A) as well as the 25th word (C) to confirm whether the seed from A and B are the same, without the seed itself.
So without the seed itself, can I determine if A + C = B
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