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Fwd: Re: how does disappearing.com's crypto work?

On 16.10.1999 at 09:30 Robert Hettinga <rah@shipwright.com> wrote:

>--- begin forwarded text
>Date: Sat, 16 Oct 1999 01:59:03 -0700
>To: cypherpunks@einstein.ssz.com, info@disappearing.com
>From: Bill Stewart <bill.stewart@pobox.com>
>Old-Subject: CDR: Re: how does disappearing.com's crypto work?
>Cc: adam@cypherspace.org, sunder@sunder.net
>Subject: Re: how does disappearing.com's crypto work?
>Sender: owner-cypherpunks@cyberpass.net
>Reply-To: Bill Stewart <bill.stewart@pobox.com>
>At 01:30 AM 10/15/1999 +0100, adam@cypherspace.org wrote:
>>I haven't seen any technical discussion of what Disappearing Inc are
>>up to.  Did the employee show up at the cypherpunks meeting as
>>My guess is that they have come up with some kind of server gated
>>forward secrecy protocol for email.  Forward secrecy is good, but
>>forward secrecy should be end-to-end, not server based, because then
>>you have to trust the server.
>Maclen Marvit from Disappearing Ink   http://www.disappearingink.com/
>spoke at the Cypherpunks meeting last Saturday.  It's good stuff.
>He started his talk by explaining the business model of what
>Disappearing Ink does, and what it does _not_ do.
>That's an important part of the discussion, because some of the things
>that it does not do are hard or impossible and people have been
>flaming them for probably doing a bad job of them.
>And it's the critical part of the "Get Money From Venture Capitalists"
>DI addresses the records destruction problem for email.
>It lets two or more willing, cooperative people have an email conversation
>with reasonable certainty that there won't be any persistent records
>kept for more than N days by any intervening servers -
>no backup tapes on email servers, no meaningful logfiles,
>nothing that SEC regulations require you to destroy about the
>potential merger & acquisition discussions you had,
>nothing that Ken Starr or the Microsoft Anti-Trust inquisitors
>or the Ollie North Follow-The-Money investigators can subpoena later,
>nothing that your business competitors can steal.
>It doesn't solve the problem of the sender or receiver making copies on
>as many people have discussed, that's not realistic.
>It doesn't solve the problem of eavesdroppers listening in while you talk;
>if you need to do that, use encryption - sending PGP-encrypted messages
>using Disappearing Ink is just fine.
>It doesn't solve the problem of logfiles indicating who send mail to whom;
>if you need a remailer, use a remailer.
>It doesn't solve the problem of cops with warrants seizing their records
>to get the messages gambino.org sent today if they're doing 60-day
>though the users can set disposal time and conditions.
>DI uses plugins to several popular email packages.
>The sender's plugin encrypts the email and does an HTTP handshake
>(using whatever SSL is available) to hand the key to the DI server.
>The recipient's plugin fetches the key using HTTP/SSL and decrypts.
>Encryption is currently Blowfish, but 3DES and TwoFish are planned.
>If the recipient doesn't have an email plugin, the message can be
>handed to DI using a web-form for decryption, but otherwise DI never sees
>or handles the messages, only the keys and message-IDs.
>I don't remember how much tracking information DI's server knows -
>it may be only a message-ID, or it may use the sender's or recipient's
>Some followon topics we suggested were the possibility of doing
>something Diffie-Hellman-like in a later release.
>I don't think we went into random number generation strategies.
>				Thanks!
>					Bill
>Bill Stewart, bill.stewart@pobox.com
>PGP Fingerprint D454 E202 CBC8 40BF  3C85 B884 0ABE 4639
>--- end forwarded text
>Robert A. Hettinga <mailto: rah@ibuc.com>
>The Internet Bearer Underwriting Corporation <http://www.ibuc.com/>
>44 Farquhar Street, Boston, MA 02131 USA
>"... however it may deserve respect for its usefulness and antiquity,
>[predicting the end of the world] has not been found agreeable to
>experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'