Subject: Re: [Bitcoin-development] Coinbase reallocation to discourage Finney attacks

From: Mike Hearn <[email-masked]>
Date: Thu, 24 Apr 2014 17:34:39 +0200

Thanks Sergio!

On Thu, Apr 24, 2014 at 5:13 PM, Sergio Lerner <[email-masked]>wrote:

> For more information you can check my post:
> http://bitslog.wordpress.com/2014/02/17/5-sec-block-interval/
> Also NimbleCoin is a new alt-coin that uses 5-sec block intervals, allows
> 100 tps and .... it's based on BitcoinJ (NimbleCoinJ now). So not only it
> is possible, but it was coded by Mike itself.
>

Fascinating! I think that's the first time I heard of an alt coin entirely
based on bitcoinj as its core implementation. Looking forward to your
release.

My understanding is that dogecoin suffers somewhat from having so many
headers. SPV clients have to download them all in sequence so the more
blocks you have, the more data they must download and thus the slower they
sync. Sync times for SPV wallets today are fast enough that unless you
spend six months in the jungle with your phone switched off, you probably
won't notice. With 5 second block times unless there's some other solution
you'd have much worse UX.

BTW, Pieter experimented with relaying blocks as hash lists (actually
merkleblocks) and I believe he found that it could often fail and be slower
if the mempools were not quite synced. At any rate, it was apparently more
complicated than it looked. That may be a side effect of trying to reuse
the Bloom filtering code however.

> Another solution to achieve <5 secs block intervals is this:
> http://bitslog.wordpress.com/2014/03/20/mincen-a-new-protocol-to-achieve-instant-payments/
>

MinCen looks like a rather interesting idea. I will read the paper.