[BitTorrent] Re: Request for protocol extension: get_info/info messages

Iain Wade iwade at optusnet.com.au
Mon Jan 17 00:23:01 EST 2005

Hi Bill.

> I think it's worth adding simple extensions to help keep the ISPs happy.
> The cache look-up is a little scary, but it could be an option that
> users could turn off.  I know I'd keep that option on.

Fantastic :-)

> The get_info/info is a fairly simple handshake, though I don't like it's
> having such a large load.  I'd prefer an incremental mechanism like the
> piece_info/piece_correct handshake.  Anyone benefiting from the cache-
> lookup extension would probably also support the related extension in
> the peer protocol, so someone would be there to help authenticate pieces
> as long as there was anyone interested in downloading from your cache.


Some other pieces of information needed are total size and piece size.
If the cache needs this information from a client, how can it verify
the accuracy of that information? In the get_info solution they are a
validated portion of the info blob.

Let me ask, if I were to implement something along these lines (with a
significantly larger patch) would people be more accepting? Bram?

> Would this be a good point to introduce Merkle hash trees, or should we
> wait for BT2?  The idea is that the get_info/info handshake would return
> a Merkle hash root for the torrent, rather than the whole info blob.  It
> would be a tiny message.  Then, we'd have a get_authentication_path /
> authentication_path handshake to authenticate the piece data.  Only path
> data up to a requested level in the tree would be returned.

I'm interested, but have no exposure to these algorithms. I guess for
them to be usefull I would still like to see them in a validated info
blob payload and that would require all clients to be updated.. BT2

Thanks for your views.

Yahoo! Groups Links

<*> To visit your group on the web, go to:

<*> To unsubscribe from this group, send an email to:
    BitTorrent-unsubscribe at yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:

More information about the BitTorrent mailing list