Subject: Re: [bitcoin-dev] UTXO growth scaling solution proposal

From: Lucas Clemente Vella <[email-masked]>
Date: Fri, 21 Jul 2017 16:59:42 -0300

2017-07-21 16:28 GMT-03:00 Major Kusanagi via bitcoin-dev <
[email-masked]>:

> [...] But the fact is that if we want to make bitcoins last forever, we
> have the accept unbounded UTXO growth, which is unscalable. So the only
> solution is to limit UTXO growth, meaning bitcoins cannot last forever.
> This proposed solution however does not prevent Bitcoin from lasting
> forever.
>

Unless there is a logical contradiction in this phrasing, the proposed
solution does not improves scalability:
 - "Bitcoins lasting forever" implies "unscalable";
 - "not prevent Bitcoin from lasting forever" implies "Bitcoins lasting
forever";
 - Thus: "not prevent Bitcoin from lasting forever" implies "unscalable".

In practice, the only Bitcoin lost would be those whose owners forgot about
or has lost the keys, because everyone with a significant amount of
Bitcoins would always shift them around before it loses any luster (I
wouldn't bother to move my Bitcoins every 10 years). I don't know how to
estimate the percentage of UTXO is actually lost/forgotten, but I have the
opinion it isn't worth the hassle.

As a side note, your estimate talks about block size, which is determines
blockchain size, which can be "safely" pruned (if you are not considering
new nodes might want to join the network, in case the full history is
needed to be stored somewhere). But UTXO size, albeit related to the full
blockchain size, is the part that currently can not be safely pruned, so I
don't see the relevance of the analysis.

-- 
Lucas Clemente Vella
[email-masked]