Process for exchange of rights between microprocessor cards

• US 5,247,578 A
• Filed: 01/22/1992
• Issued: 09/21/1993
• Est. Priority Date: 01/22/1991
• Status: Expired due to Term

• Current Assignee: France Telecom SA (Orange S.A.)
• Original Assignee: France Telecom SA (Orange S.A.)
• Inventors: Pailles, Jean-Claude, Remery, Patrick, Vallee, Francoise
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US07/823,770
• Time in Patent Office: 608 Days
• Field of Search: 380/24, 380/45, 235/379, 235/380
• US Class Current: 705/65
• CPC Class Codes: G06Q 20/06 Private payment circuits, e.g. involving electronic currency used among participants of a common payment scheme
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G06Q 20/3676 Balancing accounts
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system

Abstract

A process for exchange of rights between microprocessor cards, wherein multiple keys (K1, K2, . . . ) and varied keys (Ka5, Kb3) are used. A card to be debited calculates a voucher with varied key (Ka5) that the card to be credited reconstitutes. The process has application to electronic payment.

Claims

1. Process for exchange of rights between microprocessor cards consisting in debiting a first card (A) by a certain amount (M) and in crediting a second card (B) by this same amount (M), wherein:

cards (A) and (B) are identified by identities, respectively (a) and (b),

card (B) to be credited identifies itself to card (A) to be debited by sending its identity (b) and a number (N) that it has selected to card (B) and card (B) indicates an amount (M) of the rights to be exchanged,

card (A) to be debited verifies if its balance of rights is at least equal to requested amount (M),

in the affirmative, card (A) to be debited reduces its balance of amount (M) and calculates a voucher, which is a function F of amount (M), of identify (b) of card (B) to be credited and of number (N), or F(M,b,N),

card (A) to be debited sends this voucher F(M,b,N) to card (B) to be credited,

card (B) to be credited receives this voucher F(M,b,N), and deducts from it amount (M), identity (b) and number (N),

card (B) to be credited verifies if calculated amount (M) is indeed the requested amount (M), if the calculated identity (b) is indeed its own and if the calculated number (N) is indeed number (N) that it had selected,

in the affirmative, card (B) to be credited changes number (N) for the next exchange and exchanges its balance of amount (M) in question, this process comprising using the function F to calculate voucher C, as defined and used by the following operations;

defining in advance multiple ciphering keys (K1, K2, . . . , Km, . . . , Kn, . . . ),

storing in card (B) to be credited one of these multiple keys, or (Kn), where key number n is a function (u) of identity (b) of card (B), (u(b)=n),

storing in card (A) to be debited certain varied keys Ka1, Ka2, . . . , Kan, . . . which are each a function of multiple keys K1, K2, . . . and of identity (a) of card (A) to be debited, these varied keys being loaded in card (A) during its customization,

having card (A) to be debited receive identity (b) of card (B) to be credited and calculate row n of the varied key by function u(b) and deduct from it that of varied keys Kan with which it is to calculate voucher (C),

having card (B) to be credited calculate varied key Kan which was used in the calculation of the voucher that it received and this with its own key (Kn) and with identity (a) corresponding to card (A) to be debited, card (B) to be credited then being able to decipher voucher C with this varied key Kan.

2. Process according to claim 1, wherein each card (A) or (B) is to be either debited or credited:

storing in card (A) one of the multiple keys, or Km, where key number m is a function (u) of the identity of the card (u(a)=m), storing in card (B) varied keys Kb1, Kb2, . . . , Kbm, making it possible for card (B) to calculate a voucher intended in particular for a card (A) of identity m with varied key Kbm, card (A) receiving such a voucher reconstituting this key with its key Km and with b.