From: Gary Howland <gary@systemics.com>
Date: Wed, 16 Oct 1996 04:42:24 -0700 (PDT)
To: scottb@aca.ca
Subject: Re: extortion via digital cash
Message-ID: <199610160940.LAA20943@internal-mail.systemics.com>
MIME-Version: 1.0
Content-Type: text/plain


> Although Digicash's ecash offers anonymity to the payor it does not to the
> payee.  The reasons have to do with the way coins are blinded.  So LE
> could, with the bank's cooperation, easily associate the two sides of a
> transaction.  This was intentional on Chaum's part, either for moral or
> practical political considerations.  Its probably only a relatively minor
> patch to allow one ecash purse (the kidnapper's) to generate the blind
> token values so that another (similarly patched) purse (the vicitim's) can
> submit them to the mint and return the minted coins to the kidnapper (e.g.,
> by posting on a popular Usenet group).

Probably more than a minor patch, but doable nonetheless.

> In this scenario the only
> reasonable way left to track the money is via linkage (the size and timing
> of deposits and withdrawls in the kidnapper's account).

I can't see any reasonable way to track money obtained using the
double blind protocol - after all, the kidnapper does not even
need to have an account.

Best regards,

Gary
--
"Of course the US Constitution isn't perfect; but it's a lot better
than what we have now."  -- Unknown.

pub  1024/C001D00D 1996/01/22  Gary Howland <gary@systemics.com>
Key fingerprint =  0C FB 60 61 4D 3B 24 7D  1C 89 1D BE 1F EE 09 06