Re: Anonymity: A Modest Proposal

[loki@obscura.com (Lance Cottrell)]

-----BEGIN PGP SIGNED MESSAGE-----

I think the idea of a token has come up before. I think it is a good idea.
The token should have some expiration information in it so the remailer
need not keep it around forever (or it could just "forget" all token older
than 3 months). Right now there is not much spare room in the Mixmaster
headers.

There are several ideas for improvements in Mixmaster that will require the
adoption of an incompatible message format. I plan to collect them and
implement them all at once. One of the ideas is an expiration date in the
message to keep it from ever being replayed (even after the remailer
expires its record of the message ID).

        -Lance

At 7:43 AM 10/26/95, Adam Shostack wrote:
>Lance Cottrell wrote:
>
>| How open is the protocol? Is there and API for it? Does anyone know how big
>| the coins are? There will have to be room for one per header in Mixmaster.
>| Do they vary in size, or are all coins identical? There is so much stuff to
>| try to keep track of all at once! :/
>
>        If the coin is bigger than a Mix header has room for, does it
>have room for an arbitrary token?
>
>        I send a message to the mixmaster I'd like to use, containing
>a coin and a large arbitrary number.  I then put that number in a list
>I maintain of the tokens I can spend with that mixmaster.
>
>        The mixmaster cashes the coin at once[1], and puts my number
>into a list of 'paid' tokens it will accept.
>
>        When I want to spend the token, I put that in the message
>header block.   Since its smaller than the coin, its easier to put in
>the header than the coin.
>
>        This scheme also reduces mapability between the coin and the
>message, since they are not strongly correlated in time as they would
>be if they were included in the message.  This seems to be a stronger
>win than the size benefit that caused me to suggest this.
>
>        [1] Other than the time mapping win, I could also see spending
>a few bucks at the start of each month to be able to use any
>mixmaster.  The mixmasters would, by cashing my coins early, win on
>the float between the time they get my money and the time they provide
>service.  Icing on the cake.
>
>Adam
>

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQEVAwUBMI/NvfPzr81BVjMVAQGcbgf/b9wzPqGoijggurIm3uGiddSyaz2uAEXj
65INp6g/Va/Yf1q3+vQfyfixs3jviihmPMgepjs/deQqV5qxgEh05kbyvgKDf8wX
vh8cVLTYMKpqGOU34K/9jLOXD9gZqvKBdDy9Z5YsLimDRV3ju9uRpBSLnUaiI1rU
whpP+py/hqgFl0DL4Ybx5PBZDbcSkRhSqmlnx46/hbyY/bnaiTplPtMAU8oHZTK6
VOSB3hsPtfpGuKwCqe60WeZZDQygPbD6aDW+BZl4kMSv5+1kf4/aHECCOUqfzmvc
O1Jmr6K8wLLtp/S12qRKh4SIEea9TUqN4PoV6YGQTBV1gM6MxC/GrQ==
=qSuu
-----END PGP SIGNATURE-----

----------------------------------------------------------
Lance Cottrell   loki@obscura.com
PGP 2.6 key available by finger or server.
Mixmaster, the next generation remailer, is now available!
http://obscura.com/~loki/Welcome.html or FTP to obscura.com

"Love is a snowmobile racing across the tundra.  Suddenly
it flips over, pinning you underneath.  At night the ice
weasels come."
                        --Nietzsche
----------------------------------------------------------