Bitcoin Forum
June 20, 2018, 08:11:51 AM *
News: Latest stable version of Bitcoin Core: 0.16.1  [Torrent]. (New!)
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: Bitcoins biggest vunerability  (Read 759 times)
Anon136
Legendary
*
Offline Offline

Activity: 1540
Merit: 1092



View Profile
April 18, 2013, 03:52:32 PM
 #1

I believe the difficulty re-targeting algorithm is by far bitcoins biggest weakness and ill explain.

Imagine that another alt coin very similar to bitcoin comes onto the scene and gains prominence. Lets say its similar to bitcoin in that it uses sha256 proof of work and re-targets in the same manner as bitcoin. So what happens is miners first mine bitcoin and the difficulty re-targets up, when this happens miners begin to jump ship and instead mine altcoin. After the next re-target bit coin re-targets down and altcoin re-targets up, with each new re-target more miners switch back and forth between bitcoin and altcoin attempting to capitalize on the chain that has a lower difficulty.

This COULD create oscillations that resonate and exacerbate with time. Untill eventually it gets so bad that no miners bother to mine the coin whos blocks are coming in once per hour or once per day. One of the two coins dies entirely or is forced to fork and adopt a more adaptive re-targeting algo.

the good news is it should be relatively simple to get consensus on this fork since the chain would be totally unusable until after the fork.

ok tell me what you guys think about this observation. Im pretty sure im right about this but open to the possibility that im not. If i am correct, is gaven aware of this?

Rep Thread: https://bitcointalk.org/index.php?topic=381041
If one can not confer upon another a right which he does not himself first possess, by what means does the state derive the right to engage in behaviors from which the public is prohibited?
The World's Betting Exchange

Bet with play money. Win real Bitcoin. 5BTC Prize Fund for World Cup 2018.

Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1529482311
Hero Member
*
Offline Offline

Posts: 1529482311

View Profile Personal Message (Offline)

Ignore
1529482311
Reply with quote  #2

1529482311
Report to moderator
1529482311
Hero Member
*
Offline Offline

Posts: 1529482311

View Profile Personal Message (Offline)

Ignore
1529482311
Reply with quote  #2

1529482311
Report to moderator
matt4054
Legendary
*
Offline Offline

Activity: 1526
Merit: 1000


BitcoinQueue.com


View Profile WWW
April 18, 2013, 04:39:36 PM
 #2

I think this is already happening to altchains like TRC recently and maybe PPC to a lesser extent. The former recently had to change the retargeting algo (following a takeover attempt that was explained here on bitcointalk), the latter already had, AFAIK.

I believe Bitcoin can learn from these real-life experiences should any SHA256 chain become too attractive and most miners switch to it (still unlikely at this stage IMHO). Both of them have survived until now, though TRC's future looked uncertain for a couple of days.
DeathAndTaxes
Donator
Legendary
*
Offline Offline

Activity: 1218
Merit: 1004


Gerald Davis


View Profile
April 18, 2013, 04:56:26 PM
 #3

Any SHA256 alt-coin which doesn't use merged mining runs the risk of being 51% attacked in the cradle.  Any SHA256 based alt-coin which does use merged mining means the hashrate for both chains (btc & alt) will remain stable regardless of the shifting demand between the two coins.
Anon136
Legendary
*
Offline Offline

Activity: 1540
Merit: 1092



View Profile
April 18, 2013, 05:03:32 PM
 #4

yea thats the thing about this vulnerability, it would almost certainly kill the alt coin and not the bitcoin though not necessarily if the altcoin is atleast close to the popularity of bitcoin.

Rep Thread: https://bitcointalk.org/index.php?topic=381041
If one can not confer upon another a right which he does not himself first possess, by what means does the state derive the right to engage in behaviors from which the public is prohibited?
astor
Jr. Member
*
Offline Offline

Activity: 39
Merit: 0


View Profile
April 18, 2013, 06:17:54 PM
 #5

A solution to this is to apply control theory to the adjustment.
Anon136
Legendary
*
Offline Offline

Activity: 1540
Merit: 1092



View Profile
April 18, 2013, 07:11:26 PM
 #6

A solution to this is to apply control theory to the adjustment.

idk much about control theory but i can think of a crude solution pretty easily. Retarget every block and compare the last 10 blocks to the 10 blocks before that. If the average hashing power for the last 10 blocks was lower than the average hashing power for the 10 blocks before that adjust down, if the average hashing power for the last 10 blocks was higher than the average hashing power for the 10 blocks before that adjust up.

but yea im sure thats a pathetic attempt compared to what a "control theorist" could devise

Rep Thread: https://bitcointalk.org/index.php?topic=381041
If one can not confer upon another a right which he does not himself first possess, by what means does the state derive the right to engage in behaviors from which the public is prohibited?
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!