Subject: Re: [Bitcoin-development] Protocol extensions

From: "theymos" <[email-masked]>
Date: Sun, 18 Dec 2011 11:09:39 -0600

On Sat, Dec 17, 2011, at 05:27 PM, Jordan Mack wrote:
> I don't like the idea of a header only client, unless this is just an
> interim action until the full block chain is downloaded in the
> background. Development of these types of clients is probably
> inevitable, but I believe that this breaks the most fundamental
> aspects of Bitcoin's security model. If a client has only headers, it
> cannot do full verification, and it is trusting the data from random
> anonymous peers.

A headers-only client is much better than trusting anyone, since an
attacker needs >50% of the network's computational power to trick
such clients.

For everyone to keep being a full node, hardware costs would need to
constantly go down enough for all nodes to be able to handle enough
transactions to meet demand. If hardware doesn't become cheap enough
quickly enough, either some people would be unable to handle being full
nodes, or the max block size wouldn't rise enough to meet demand and
transaction fees would become noncompetitive.