Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: Colorblind on February 13, 2018, 09:05:08 AM



Title: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: Colorblind on February 13, 2018, 09:05:08 AM
This is very interesting attack vector on currencies that utilize same POW algo. (In this case contributing fraction of Bitcoin hash power can totally screw Bitcoin Cash, allowing double spend).
 
https://youtu.be/_cuImsvmSf4

Thoughts?


Title: Re: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: ICOgenius on February 13, 2018, 09:56:01 AM
I have been spreading this video myself to anyone and everyone that will watch or those who even just may.  Keep up the great work!  The world must be informed of this possible danger! :-[


Title: Re: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: Colorblind on February 13, 2018, 12:06:03 PM
I have been spreading this video myself to anyone and everyone that will watch or those who even just may.  Keep up the great work!  The world must be informed of this possible danger! :-[

That's actually very interesting attack vector, that does not point at Bitcoin directly but rather utilizes it's overpowering hash rate to screw any coin with same mining algo. BCH is obvious high profile target but I think number of smaller coins can be subjected to this kind of attack as well (and entry requirements will be orders of magnitude less).






Title: Re: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: monsterer2 on February 13, 2018, 12:17:01 PM
This is very interesting attack vector on currencies that utilize same POW algo. (In this case contributing fraction of Bitcoin hash power can totally screw Bitcoin Cash, allowing double spend).
 
https://youtu.be/_cuImsvmSf4

Thoughts?

Yes, this is a common attack vector for new coins using the same hashing algorithm as established players. Basically, this is "do not do" no. 1 in the rules of PoW.


Title: Re: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: markblundeberg on February 16, 2018, 07:36:35 AM
The attack described is literally the definition of a 51% attack (https://en.bitcoin.it/wiki/Majority_attack). I don't understand why he relabels it as "withholding blocks".


Title: Re: Possible Double-Spend attack on BCash using Bitcoin Mining pool
Post by: Xynerise on February 16, 2018, 07:42:22 AM
The attack described is literally the definition of a 51% attack (https://en.bitcoin.it/wiki/Majority_attack). I don't understand why he relabels it as "withholding blocks".
To be fair, a 51% attack works by "withholding blocks" AKA private mining. It obviously won't work if the attacker broadcasts the blocks as he finds them.