Subject: Re: [Bitcoin-development] Auto-generated miner backbone

From: Mike Hearn <[email-masked]>
Date: Mon, 4 Nov 2013 13:00:16 +0100

On Mon, Nov 4, 2013 at 12:53 PM, Peter Todd <[email-masked]> wrote:

> I proposed this as a means of giving a mechanism for wallets to get
> non-sybilled peers as well.
>

Ah yes, good point.

> Doing so encourages pools to only bother connecting to other pools,
> which is a strong centralizing force.
>

They could already create such a setup, but we don't observe it in practice.

> On a technical level, the coinbase is limited in size, and people use it
> for other purposes, so lets define a standard ....

Given that IP address data is inherently transient, perhaps a better
solution is to define a short hash in the coinbase that commits to extra
data that is relayed along with block data (e.g. appended to the block
message). It can then be stored temporarily in the block db and erased
after some time, like a few months. It would therefore not really be a part
of the chain, but could be extended as we see fit with any other
semi-transient data required. A new "getextra" message would let nodes
query for it.

The hash can be short because it doesn't have to survive brute forcing
attacks longer than the expected validity period of the transient data
anyway. 80 bits would probably be overkill.