[freehaven-dev] how to retrieve fragments?

[Roger R Dingledine <arma@mit.edu>]

In the original case, we said each fragment had its own PK/SK pair, and
so for a file fragmented into 20 fragments, you would do 20 separate
queries, and then attempt to recreate the file based on the responses you
get.

This has the benefit that you can query for just a single fragment (eg if
you're checking to see if it's still there).

In the new proposal, we propose to have a single PK/SK pair for the entire
file, and each fragment is signed by that key. This allows us to confirm
that each fragment is in fact part of the original file that was fragmented.
It also means that when we query for the file, we simply broadcast "anybody
have any fragments signed by this key?"

However, we've lost the ability to do a fine-tuned (per-fragment) query.

This means that we'll be pulling in (and ignoring) all the other fragments,
every time we do a verify on a fragment.

Is this ok?

--Roger