Quote from: gavinandresen on July 14, 2010, 12:42:32 AM

And I expect most of us will be running lightweight clients that just keep our wallets, sign transactions, and send and receive transactions to the ultra-fast nodes that ARE looking at every transaction.

Is this possible? What would this look like? From a technical perspective what does a "lightweight client" look like for you? My understanding is that the Bitcoin client needs the entire block chain in order to establish trust.

I am just thinking out loud here...

Although the peer-to-peer model is certainly novel perhaps it seems to me to be somewhat utopian. Bear with me for a minute here (I am not trying to troll). Consider banks. Banks have a system whereby they can work together efficiently. I take take money out of a ATM from bank X even though I bank with bank Y. Banks loan money to each other. They are generally cooperative. Instead of every Tom, Dick & Harry having a Bitcoin client on his/her PC (or smartphone) participating in an open P2P network, perhaps there is a collection of Bitcoin "banks" who provide the service of hosting and "peering" the Bitcoin block chain. These are large enough organizations that they can afford the bandwidth and hardware needed to maintain an infinitely long block chain with a million (or more) transactions a day. These banks would still be peer-2-peer, and hopefully also completely open. Ideally anybody could participate in the peer-2-peer network, its just that the average person won't because of the barrier to entry. These banks still operate using the same fundamental technology we have to day. All of the beautiful facets of Bitcoin are preserved, except that the number of active participants is somewhat reduced. Anybody that _wanted_ to participate still could.

The problem remaining would be the typical "last mile" problem. How does Tom (or Dick or Harry) perform transactions? Well the issue becomes much more straight forward at this point. Now the trust only has to be between two parties (the "bank" and Tom). This really becomes more of a proxy issue. Now Tom has to send a transaction request through his "bank". It might even be possible to bake into Bitcoin a protocol for proxy transactions.

Anyway...This is just my 2 cents. I would really like a tangible answer to this problem because it seems foundational to the success of this endeavor to me.