Seeding and Leeching: Collaborative Preservation using BitTorrent

Ashley Blewer, #amia15

Torrents in archives

Torrents as archives

Copy, right?

Tech stacks on stacks

PROTOCOL

HTTP?

(GET, PUT, POST, DELETE, etc)

BitTorrent protocol requirements

a web server
'metainfo' file*
torrent tracker
'original' downloader
end user web browsers
end user downloaders

BitTorrent as a file

BitTorrent as a tracker

Peers

Handshake

TCP

Two things

1. Are you busy?
2. Are you interested?

Metainfo file!

Randomness

1-to-1

Switching gears

Oh look, the NDSA levels of preservation! I don't expect you to be able to read this, but I expect that all of you have this completely memorized already, right? Thinking about the NDSA levels of preservation: It's pretty easy to cover all levels of preservation with this protocol, especially if there's institutional support behind it. But what it means is lots of people have verified copies of a digital file, this fulfills the archival mantra of LOCKSS (Lots of Copies Keep Stuff Safe). The more copies there are distributed, the stronger a file is. Fixity is sorta constantly being checked. Torrents use checksums to verify file fixity as well! So they are already archivally sound in that way! Torrents are validated via an MD5 hash. And in fact this hash must validate in order to work and continue to be part of the same torrent swarm. Security can be monitored by making the torrent private, metadata can and usually is packaged, and media files are interoperable, using formats and codecs that allow for the largest possible audience.

“When a file is made available using HTTP, all upload cost is placed on the hosting machine. With BitTorrent, when multiple people are downloading the same file at the same time, they upload pieces of the file to each other. This redistributes the cost of upload to downloaders, (where it is often not even metered), thus making hosting a file with a potentially unlimited number of downloaders affordable.”

$ Bandwidth $

Start doing

XFR Collective

Democracy Now!

The end

Seeding and Leeching: Collaborative Preservation using BitTorrent

Ashley Blewer, #amia15

Torrents in archives

Torrents as archives

Copy, right?

Copy, right?

Tech stacks on stacks

PROTOCOL

HTTP?

(GET, PUT, POST, DELETE, etc)

BitTorrent protocol requirements

BitTorrent as a file

BitTorrent as a tracker

Peers

Handshake

TCP

Two things

1. Are you busy? 2. Are you interested?

Metainfo file!

Randomness

1-to-1

Switching gears

$ Bandwidth $

Start doing

XFR Collective

Democracy Now!

The end

1. Are you busy?
2. Are you interested?