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Fair Auction System using Public Key Cryptosystem: a business model

IP.com Disclosure Number: IPCOM000013059D
Original Publication Date: 2001-Jun-01
Included in the Prior Art Database: 2003-Jun-12
Document File: 3 page(s) / 57K

Publishing Venue

IBM

Abstract

Disclosed is a method on construction of a fair auction system using a Public Key Cryptosystem. This method simulates on the Internet the traditional "auction box" method. Auction

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Fair Auction System using Public Key Cryptosystem: a business model

Disclosed is a method on construction of a fair auction system using a

Public Key Cryptosystem. This method simulates on the Internet the

traditional "auction box" method.

Auction

B o x

In case of the traditional ·auction box· system, every
participant of the auction writes the price on an application
form and puts it into a locked auction box once during the
auction period. In this situation, the following 2 conditions are
satisfied.

(a) The price is kept confidential until the box is open.
(b) Every participant can be convinced that the auction has been
run fairly. (No
modification of the written prices in the box is possible.)

In this new auction system on the Internet, the process goes on
as follows.

1. The host of the auction announces the number Lp, Ld, which
will be used through all the auctions he/she will hold. Lp is
the length of the digit of the prices which indicates practically
infinity. Ld is the length of the digit of dummy factors which
will be used to guarantee the above condition (a). Lt denotes the
sum i.e., Lp + Ld .

2. The host also prepares on the Web site a table for auction to
which every applicant will be able to write his/her price.

3. Every applicant Ai (i=1,2,..);

3.1 determines his/her price Pi whose length is Lp, (left padding
0 if necessary)

3.2 chooses any dummy factor Di, whose length is Ld,

3.3 generates his/her encryption key Ei, based on Public Key
theory,

1

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3.4 calculates Vi = Di || Pi (||: concatenation), in which the
length of Vi therefore becomes Lt.

3.5 calculates Xi = Ei(Vi),

3.6 writes the name Ai, the encryption key Ei and Xi to the
auction table.

4. As time goes on, the auction table looks like this.

Name Encryption
Valuekey

A1 E1 X1 A2 E2 X2

· An...