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Bitcoin => Development & Technical Discussion => Topic started by: COBRAS on October 26, 2021, 03:31:41 PM



Title: Interesting Idea about deviding one ec point to eanother.
Post by: COBRAS on October 26, 2021, 03:31:41 PM
Hi

Source - https://crypto.stackexchange.com/questions/95778/notation-question-dividing-2-elliptic-curve-points-producing-a-third-point
Quote

....so does division here actually correspond to subtraction in the exponent? i.e. if A = g^a, B = g^b then A / B = g^(a-b) ?

What you think about this ?


Title: Re: Interesting Idea about deviding one ec point to eanother.
Post by: garlonicon on October 26, 2021, 08:15:48 PM
Multiplication and division is possible if you know some public key and you want to multiply or divide it by some private key (it can be done in exactly the same way as multiplying or dividing by the base point, all you need is just changing your starting point). It is impossible if you have two public keys, because then ECDSA would be broken.


Title: Re: Interesting Idea about deviding one ec point to eanother.
Post by: MixMAx123 on October 26, 2021, 08:42:38 PM
The division basically works just as well as multiplication by multiple addition. By multiple dividing can be divided.

I read again and again from an "impossible" division, which is wrong and a misleager.
The multiplication by addition and the division function
But lasts very long, longer than the time of the universe as it exists.
For multiplication, there is an abbreviation, an algorithm that can be calculated much faster. There is no abbreviation for the division. That's all.


An example. Imagine your private key is 15.

So they add 15 x g = g + g + g + g + g + g + g + g + g + g + g + g + g + g + g = pub

Going fast.

But if you have 0x129D12802FFDB88BF992F66D4BC1E145441030250B0AF6E3C72E6C56D766C799 x G
This would not have to be able to create a PC in the time of her life.
If he would calculate it in this way.


Title: Re: Interesting Idea about deviding one ec point to eanother.
Post by: math09183 on October 27, 2021, 02:17:58 PM
Is there any way to ignore (hide) all the posts and threads started by that guy?


Title: Re: Interesting Idea about deviding one ec point to eanother.
Post by: a.a on October 27, 2021, 02:23:24 PM
Yeah, you can ignore this big brain guy
Remembers me if this:
https://youtu.be/LQCU36pkH7c

 There is an Ignore link in each post.


Title: Re: Interesting Idea about deviding one ec point to eanother.
Post by: NotATether on October 27, 2021, 07:15:17 PM
Division in that particular form is nonsensical I.e. you can't just take a-b, the difference between those two points, and then multiply that by G to get a priv key. Actually this operation doesn't even result in a privkey it makes a public key.