Re: Crypto codes #1

From: Charlie Strauss <cems_at_earthlink_dot_net>
Date: Tue May 24 2005 - 00:23:31 CDT

On May 22, 2005, at 12:09 AM, Edward Cherlin wrote:

> On Thursday 19 May 2005 11:36, charlie strauss wrote:
>
>> I'm not sure I understood the entire context of the discussion
>> but one thing cuaght my eye:
>>
>> "2) Each ballot contains (as printed strings or in a barcode):
>>
>>> for bv = ballot-id + vote-string:
>>> e = encrypt(k, hash(bv))
>>> print bv + hash(bv) + e
>>>
>>> (3) At finalization, k is revealed publicly.
>>>
>>
>> If the hash function is known or knowable does not this reveal
>> you ballot and provide a effective receipt? That is to say
>> it's going to be fairly trivial, by crypto standards to invert
>> the hash of a ballot string I would suspect.
>>
>
> We are using hashes as signatures, not as encryption. The ballot
> is already known, and will be published with the hash. This
> makes it infeasible to change one ballot and its hash, and keep
> the hash for the complete election unchanged.

the point was that if you tell someone your hashcode before the keys
are published or the hashes are published you can prove to them how
you voted, since only you would be able to know that hash. Myabe I'm
still missing the order of operations here...

>
> --
> Edward Cherlin
> Generalist & activist--Linux, languages, literacy and more
> "A knot! Oh, do let me help to undo it!"
> --Alice in Wonderland
> http://cherlin.blogspot.com
> _______________________________________________
> OVC discuss mailing lists
> Send requests to subscribe or unsubscribe to
> arthur@openvotingconsortium.org
>

_______________________________________________
OVC discuss mailing lists
Send requests to subscribe or unsubscribe to arthur@openvotingconsortium.org
==================================================================
= The content of this message, with the exception of any external
= quotations under fair use, are released to the Public Domain
==================================================================
Received on Tue May 31 23:17:47 2005

This archive was generated by hypermail 2.1.8 : Tue May 31 2005 - 23:17:53 CDT