[EM] untraceable receipts

[Rob Speer]

On Wed, Nov 12, 2003 at 04:38:07PM -0800, Ernest Prabhakar wrote:
> >What was the goal of that receipts???
> >1) To remember who you voted for?
> >or
> >2) To verify your vote was counted?
> >
> >1) is silly.
> >If 2) is possible for you, it is possible for the mafia too. ;-)
> 
> I don't get #2 at all.  I've actually been confused by this.  If by 
> receipt we mean a full plaintext list of all the votes you made, then I 
> can see how it would be a security risk.   However, it would think it 
> would be fairly trivial to create an ecrypted receipt that could 
> -verify- a vote without actually revealing the vote (at least without 
> massive conspiracy).
> 
> For example, each vote could be used to create a 'private key - public 
> key' pair, as in public key infrastructures (PKI).    The private key 
> would be used to hash a cumulative vote tally, and the public key would 
> be given to the voter (along with: you are the 1523rd voter).    It 
> should be mathematically possible to audit the vote tallies, and for 
> the voter to confirm that his private key was used at a given step, 
> without revealing any information about the private key.  The first 
> voter would hash a random seed, so that even his/her vote would not be 
> decipherable.

So you get to confirm that you voted, but not that your vote went to the
person you wanted to vote for?

I don't think that's what people are looking for in verifiability.

Then again, it's probably the best kind of verifiablity you can get
without enabling coercion. But that's a really complicated system for
such a small gain.

-- 
Rob Speer