Subject: [bitcoin-dev] idea post: trimming and demurrage

From: Patrick Sharp <[email-masked]>
Date: Mon, 25 Sep 2017 15:54:16 -0600

Hello Devs,

I am Patrick Sharp. I just graduated with a BS is computer science. Forgive
my ignorance.

As per bip-0002 I have scoured each bip available on the wiki to see if
these ideas have already been formally proposed and now as per bip-0002
post these ideas here.

First and foremost I acknowledge that these ideas are not original nor new.

Trimming and demurrage:

I am fully aware that demurrage is a prohibited change. I hereby contest.
For the record I am not a miner, I am just aware of the economics that
drive the costs of bitcoin.

Without the ability to maintain some sort of limit on the maximum length or
size of the block chain, block chain is not only unsustainable in the long
run but becomes more and more centralized as the block chain becomes more
and more unwieldy.

Trimming is not a foreign concept. Old block whose transactions are now
spent hold no real value. Meaningful trimming is expensive and inhibited by
unspent transactions. Old unspent transactions add unnecessary and unfair
burden.

   - Old transactions take up real world space that continues incur cost
   while these transactions they do not continue to contribute to any sort of
   payment for this cost.
   - One can assume that anybody with access to their bitcoins has the
   power to move these bitcoins from one address to another (or at least that
   the software that holds the keys to their coins can do it for them) and it
   is not unfair to require them to do so at least once every 5 to 10 years.
   - Given the incentive to move it or lose it and software that will do it
      for them, we can assume that any bitcoin not moved is most likey
therefore
      lost.
      - moving these coins will cost a small transaction fee which is fair
      as their transactions take up space, they need to contribute
      - most people who use their coins regularly will not even need to
      worry about this as their coins are moved to a change address anyway.
   - one downside is that paper wallets would then have an expiration date,
   however I do not think that a paper wallet that needs to be recycled every
   5 to 10 years is a terrible idea.

Therefore I propose that the block chain length be limited to either 2^18
blocks (slightly less than 5 years) or 2^19 blocks, or slightly less than
10 years. I propose that each time a block is mined the the oldest block(s)
(no more than two blocks) beyond this limit is trimmed from the chain and
that its unspent transactions are allowed to be included in the reward of
the mined block.

This keeps the block chain from tending towards infinity. This keeps the
costs of the miners balanced with the costs of the users.

Even though I believe this idea will have some friction, it is applicable
to the entire community. It will be hard for some users to give up small
benefits that they get at the great cost of miners, however miners run the
game and this fair proposal is in in their best interest in two different
ways. I would like your thoughts and suggestions. I obviously think this is
a freaking awesome idea. I know it is quite controversial but it is the
next step in evolution that bitcoin needs to take to ensure immortality.

I come to you to ask if this has any chance of acceptance.

-Patrick