Bitcoin Forum
January 20, 2017, 08:07:21 AM *
News: Latest stable version of Bitcoin Core: 0.13.2  [Torrent]. (New!)
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: Strong solution, weak solution - orphanned block process  (Read 1236 times)
marcus_of_augustus
Legendary
*
Offline Offline

Activity: 2128



View Profile
May 31, 2011, 09:08:39 AM
 #1

Just wondering if there is an opening for the following type of questionable behaviour on the network.

A large miner with an incentive to collect as many solution blocks as possible has a program running to filter their block solutions outputs.

A weak solution is broadcast immediately to the network to earn the rewards, however if a sufficiently strong solution is found it is withheld until a competing node broadcasts an inferior solution. At this point, the miner then broadcasts their strong solution confident it will be accepted across the network and the weaker competing solution will be orphaned.

In this way, the large miner is effectively reducing the power of the competition on the rest of the network and thus keeping more of the rewards for themselves. Anything to stop this?

Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1484899641
Hero Member
*
Offline Offline

Posts: 1484899641

View Profile Personal Message (Offline)

Ignore
1484899641
Reply with quote  #2

1484899641
Report to moderator
1484899641
Hero Member
*
Offline Offline

Posts: 1484899641

View Profile Personal Message (Offline)

Ignore
1484899641
Reply with quote  #2

1484899641
Report to moderator
Pieter Wuille
Legendary
*
qt
Offline Offline

Activity: 1036


View Profile WWW
May 31, 2011, 09:15:24 AM
 #2

Blocks count proportional to their difficulty, i.e. the fraction of the target they had to beat - not the actual fraction of it they reached.

There is no way to have a better solution for a given block when one is already created, as the difficulty is fixed.

Only when doing a multi-block attack crossing a retarget boundary (height multiple of 2016), one can influence the effect of the retarget, and thereby the difficulty.

aka sipa, core dev team

Tips and donations: 1KwDYMJMS4xq3ZEWYfdBRwYG2fHwhZsipa
marcus_of_augustus
Legendary
*
Offline Offline

Activity: 2128



View Profile
May 31, 2011, 09:19:15 AM
 #3

Blocks count proportional to their difficulty, i.e. the fraction of the target they had to beat - not the actual fraction of it they reached.

There is no way to have a better solution for a given block when one is already created, as the difficulty is fixed.

Only when doing a multi-block attack crossing a retarget boundary (height multiple of 2016), one can influence the effect of the retarget, and thereby the difficulty.

Hmmm, okay I must not understand the orphanning process can you elaborate on that?

 How does a block get orphaned if there is no such thing as a "better" solution?

Pieter Wuille
Legendary
*
qt
Offline Offline

Activity: 1036


View Profile WWW
May 31, 2011, 09:24:54 AM
 #4

When two successor blocks B1 and B2 are generated simultaneously for a single block A, part of the network will receive B1 first, and another part B2. Both will assume the one they saw first will win, and work with that. However, if B1 is extended first with a successor block C, while B2 isn't extended yet, all nodes that were working with B2 will realize the chain containing B1 is better now (as it longer, not because they individual blocks in it are better), and switch to A->B1->C as best chain.

aka sipa, core dev team

Tips and donations: 1KwDYMJMS4xq3ZEWYfdBRwYG2fHwhZsipa
marcus_of_augustus
Legendary
*
Offline Offline

Activity: 2128



View Profile
May 31, 2011, 09:28:05 AM
 #5

When two successor blocks B1 and B2 are generated simultaneously for a single block A, part of the network will receive B1 first, and another part B2. Both will assume the one they saw first will win, and work with that. However, if B1 is extended first with a successor block C, while B2 isn't extended yet, all nodes that were working with B2 will realize the chain containing B1 is better now (as it longer, not because they individual blocks in it are better), and switch to A->B1->C as best chain.

Ah, thanks.

Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!