From: "James A. Donald" <jamesd@echeque.com>
Date: Mon, 18 Aug 1997 04:39:38 +0800
To: Alan <cypherpunks@toad.com>
Subject: Re: FCPUNX:Getting ecash without an MTB account
Message-ID: <199708172027.NAA14757@proxy3.ba.best.com>
MIME-Version: 1.0
Content-Type: text/plain



On Fri, 15 Aug 1997, Mike wrote:
>> Are you referring to the receiver anonymous protocol?
>> 
>> This is how I understand that protocol,
>> 
>> Alice wants to receive e$1 from Bob. She creates a random number, blinds
>> it, and gives the blinded number to Bob. He shows the number to the
>> Mint, asking for a withdrawal of e$1 with a signature on this coin
>> number. Bob gives the signed and still blinded coin to Alice. She
>> unblinds it and spends it, end of story.

At 10:24 AM 8/15/97 -0700, Alan wrote:
> Actually the coin is intercepted and spent by Mallet.  Alice gets pissed
> at Bob because she feels cheated by him.

Mallet cannot intercept the coin, because only Alice can unblind it.

Mallet cannot provide Bob with a number blinded by him, rather than
Alice, because Alice signed the blinded number

>> I thought that in this scenario, Bob can spend the coin before he gives
>> it to Alice, 

No he cannot, because only Alice can unblind the coin.

> My understanding of the protocol is that the identity of the purchacer is
> revealed only if the coin is double spent. 

The identity of Bob is known by Alice and the bank.

No one can ever discover the identity of Alice from the coin.

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