Prepaid smart card in a GSM based wireless telephone network and method for operating prepaid cards

• US 6,415,142 B1
• Filed: 12/23/1998
• Issued: 07/02/2002
• Est. Priority Date: 04/19/1996
• Status: Expired due to Fees

• Current Assignee: Gemplus SCA (Thales SA)
• Original Assignee: Gemplus SCA (Thales SA)
• Inventors: Martineau, Philippe
• Primary Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US09/220,000
• Time in Patent Office: 1,287 Days
• Field of Search: 455/90, 455/403, 455/406, 455/407, 455/408, 455/409, 455/410, 455/411, 455/550, 455/558, 455/575, 379/114, 379/132, 379/144, 379/357
• US Class Current: 455/411
• CPC Class Codes: G06Q 20/3229 Use of the SIM of a M-device as secure element
• 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 20/363 with the personal data of a user
• CPC Class Codes: G07F 17/0014 for vending, access and use of specific services not covered anywhere else in G07F17/00 meter-controlled dispensing of liquid, gas or electricity G07F15/00
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card
• CPC Class Codes: G07F 7/0866 by active credit-cards adapted therefor G07F7/1008 takes precedence
• CPC Class Codes: G07F 7/0886 the card reader being portable for interacting with a POS or ECR in realizing a payment transaction
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: H04M 15/47 Fraud detection or prevention means
• CPC Class Codes: H04M 17/00 Prepayment of wireline communication systems, wireless communication systems or telephone systems using a coded card to authorise calls from a telephone set H04M1/675
• CPC Class Codes: H04M 2215/0148 Fraud detection or prevention means
• CPC Class Codes: H04M 2215/0192 Sponsored, subsidised calls via advertising, e.g. calling cards with ads or connecting to special ads, free calling time by purchasing goods
• CPC Class Codes: H04M 2215/2026 Wireless network, e.g. GSM, PCS, TACS
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04W 4/24 Accounting or billing

Abstract

A smart card, which in normal use in a network allows the transfer of goods/services to a user of the card from a network operator by subtracting prepaid units of value stored in the card. The card has an embedded integrated circuit with a serial number unique to each card, and a prepaid units register for storing a number of remaining units of prepaid value. In response to an interrogation, the serial number and the number of remaining prepaid units may be read out. A key number is also stored in the circuit. It has a first portion unique for each card, and a second portion which is common to a plurality of cards, but unique for a network operator. The key number in normal use of the card cannot be read from the card. An algorithm is also stored in the card, and in normal use it also is not readable from the card. A microprocessor calculates a certificate in accordance with the algorithm as a function of the key number and the number in said prepaid register, and the certificate is readable from the card.

Claims

1. A smart card, which in normal use in a network allows the transfer of goods/services to a user of the card from a network operator by subtracting prepaid units of value stored in said card in exchange for said goods/services comprising a card-shaped carrier having a terminal, and an integrated circuit embedded in said carrier and connected to said terminal;

said integrated circuit comprising

a serial number register for storing a serial number unique to each card, and which number in said register in response to interrogations at said terminal being readable at said terminal,

a prepaid units register for storing a number of units of prepaid value, and which number in said units register, in response to interrogations at said terminal being readable at said terminal,

a key number register storing a key number, which has a first portion unique for each card, and a second portion which is common to a plurality of cards, and which is unique for a network operator, said key number in normal use of said card not being readable at said terminal,

an algorithm stored in said card, said algorithm in normal use in said card not being readable in said terminal,

a microprocessor for calculating a certificate in accordance with said algorithm as a function of said key number and the number in said prepaid register, and said certificate being readable at said terminal.