[chord] Help: immutable blocks in Dhash

[Emil Sit]

Hello,

On Sat, 15 July 2006 at 08:52 (+0100), vsp wrote:
> (1) Is this scheme correct in theory?  Knowing that Dhash does
> immutable block storage, if the same person logs out of the network
> and then logs in after sometime (username john remains same) with a
> different ip address (dynamic ip addresses case), then will the scheme
> fail because there will be two blocks with same key(username) but
> different contents (ip address). If yes, then what is the way around
> this problem ?

The best way to solve this problem would be to use KEYHASH blocks.  The
key in DHash is derived from a public signature verification key (and a
salt) and the data is verified using the public key.  Each user has a
corresponding private key and signs a block indicating his location
using that key.  DHash and the other users in the system would then be
able to verify the validity of a given block by checking that the
signature validates.

-- 
Emil Sit / MIT CSAIL PDOS / http://pdos.csail.mit.edu/chord/