[Bitcoin-ml] Solving the difficulty adjustment problem by asking the opposite question

Tom Zander tomz at freedommail.ch
Tue Aug 29 14:24:30 UTC 2017


On Monday, 28 August 2017 02:38:44 CEST Jan Nightingale via bitcoin-ml 
wrote:
> >Back to the proposal, considering timestamp are unreliable
> 
> Note that network time enforcement is how Bitcoin's POW works even
> currently.

There are some mistakes in thinking here.

A blockchain is a static datastructure that can only be extended. But more 
importantly, both current and future observers of this data-structure have 
to agree on what is a valid chain.
So if I were to mark a block in the future, that is a detail that will not 
be possible for future observers to identify. It can therefore not be 
something that we disqualify a chain on.

What happens instead is that miners choose to only mine on top of certain 
blocks. They reject a block in the future because their software tells them 
to.
The result is a longer chain of blocks that have more accurate time-stamps. 
And thus the longer chain wins.


Now, if you somehow change the willingness of miners to reject blocks with a 
future timestamp. For instance by making their reward greater if the block 
is timestamp in the future, then the natural consequence is that they will 
stop rejecting blocks that were time stamped in the future.

Because any observer checking the blockchain will not be able to see at what 
time a block was generated. As such that observer will not be able to reject 
a chain abused like this.

Bottom line is that timestamps on blocks can and will be falsified. They can 
not be used for the incentive system.
-- 
Tom Zander
Blog: https://zander.github.io
Vlog: https://vimeo.com/channels/tomscryptochannel


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