GB2375427A

GB2375427A - A fare collection and general payment system

Info

Publication number: GB2375427A
Application number: GB0200353A
Authority: GB
Inventors: John Wolfgang Halpern
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-05-09
Filing date: 2002-01-09
Publication date: 2002-11-13
Anticipated expiration: 2022-01-09
Also published as: GB0200353D0; GB0210694D0; GB2375427B; GB2378031A; GB0111269D0; GB2376785A

Abstract

The fare collection and general payment system comprises an identifiable personal payment token device 8 capable of electronically storing a cash value reserve, a value reserve debited to an account and a value reserve credited to an account. The system has at least one public transport provider organised to service a demand for transport from a customer in terms of a coded starting point and a coded arrival point. These codes and other parameters are downloaded into the token device in return for a verified payment made from the token device to the transport provider or his agent. The token device can be used to purchase goods from a retailer. The system uses mobile phone transmission techniques for the sending and receiving of rule-related and security-related data such as encryption keys, account numbers of closed accounts and serial or account numbers of those said payment token devices that have received value-added updates entered by a service provider. The system may have equipment for generating random or pseudo-random numbers each associated with an access code. The access code is transmitted in a clear or a non-encrypted manner and the random numbers are transmitted in an encrypted form. The random numbers may be used as encryption keys which may be stored within said payment token device together with its access code. The keys may be updated on a daily basis.

Description

Long-tenn Security for Card-based recording and transaction systems.

In my currently processed UK patent application No 0111269, 7 entitled "Region-wide Fare Collection and General Payment System"I have a. o. indicated how the security aspect could be improved in card-based systems, especially in such as aspire to compete with the role of money. Using the latter means exchanging physically tangible entities whereas using the former means exchanging physically completely non-tangible entities. In either case, the potential exists for incurring heavy losses if fraudulent imitation is neglected.

As part of an effort to improve the long-term prospect of removing card-based payments from the said possibility, it is suggested to create a set-up which would permit encryption keys to be changed every morning, on all the days of the week. and to this end utilise the signal transmission technology already developed for mobile phones. The reason for this choice is the relatively slow data rate at which digital messages can be passed through the telephone network.

Although encryption keys may be replaced with new ones day by day, it still remains necessary to retain in memory those used during the preceding seven days or possibly for an even longer period, and have them (the keys) identified by the Reader Terminal, because not every user of the system will have to make a purchase at least once a day. And a check on card authenticity of a card presented to the terminal is an absolute requirement as part of the general security system. However, this means that also an analyst has more time available to compare various encrypted text portions, and on that basis might be able to attempt to reconstruct the algorithm circuitry. (This would be a rather difficult task because there are encryption algorithms which produce a variable word length output and for that reason, a potential hacker could not rely on computer-assisted analysis.) There is a further means of making the task even more difficult to a potential hacker, namely to alter the composition of he various functional interdependencies within the algorithm chip: that is, the text to be transmitted (or being received) is arranged to modify the machine state of the algorithm.

As a consequence, not knowing the encryption keys and not knowing the text of a particular transmission, recording the encrypted text on tape would be virtually useless.

Admittedly, it may be possible to use existing equipment and compare various text passages. But this would be feasible in practice only if the experimenter knew at the very least which encryption number is carried by his own card at a particular moment of time. This he or she cannot know since no data whatever (including key data) can be outputted from the system in the clear form, only in the encrypted form.

Therefore, in practice, the potential hacker can only make assumptions, and then test them. There are so many possibilities that along that way years may pass before anything useful has been found ; by then, the system owners may change the parameters, and nothing will be gained from the effort In other systems of encryption, results can be achieved in shorter time because of computer-aided procedures, except the key length is made gigantic (2048 bits, for

example). Such systems are not practical for card operation, especially in a transport context where card transaction speed is vital Bccause long-term security is of importance to a universally applicable card system, the here indicated encryption system may be used either in isolation or in combination with one of the mathematical encryption systems- (double encryption).

Here follows a description of the Figs 1 and 2 of the enclosed drawings.

The extended memory sections of the transmitters of mobile phone network' receive from the'financial institutions'of a country any account numbers that remain overdrawn or had been reported lost or stolen and have up to the moment not been found or returned to the owner. These last-mentioned transmissions will

probably occur via cable lines t. This record is broad-cast by mobile phone relay stations to the various Service Suppliers'Headquarters and from there to their branches o r member firms via telephone lines and/or internet lines. There may not be a need to do this more often than once a day, say, between 2am and Sam. During the same period also the following signals are programmed to be sent out from the Mobile Phone Relay Stations: Polling signals are addressed to the HQ stations of the various participant organisations. Each Polling Signal alerts the receiving stations to send its currently held encryption key encrypted by itself to the Mobile Phone Relay Station concerned where it is decrypted and tested If correct, the Random key generator 3 produces a new key (the key for the day), encrypts it with the key of the previous day, broadcasts it to the addressed HQ of the Service Supplier, is here decrypted using the key of the preceding day, and entered as the new valid key for the day. This'key replacement sequence'occurs extremely rapidly, requiring perhaps no more than fifty millisecond for each customer. After that, the polled Service Supplier transmits, encrypted with the newly acquired encryption key, the account numbers of those card holders whose cards had been automatically value-incremented during the previous day (as a service to their customers), namely by the bank-approved incremental amount (suggested value steps may be f20, 40 and 100). These numbers are stored and processed for transmission via cable 2 or mobile phone wireless to the respective financial institutions. The latter will find them at the start of business, and duly debit the respective current accounts or deduct them from the remaining credit accounts, respectively.-Item 7 symbolises any number of Readers associated with a particular user application, item 8 is the payment token.

This system will enable the individual card holder to have instant access to all small cash expenses, and even permit larger purchases, by multiple debiting of the permitted incremental update, within any limits stipulated. The fact that a single card is being given this scope is likely to lead to new card designs wherein the customer will be able to enter a PIN on the card itself for increased security or employ electronic finger print entries. Such card will also provide a display of past expenses automatically ordered by category, or by date of event It will also permit periodic transfer of all the card data to the customer's PC. This user platform will at once bring about a change likely to be welcomed by those who experienced trouble with the many paper receipts that filled their wallets. Many of these receipts were virtually illegible, most of them were of different sizes and formats, and resisted being kept together

in some orderly fashion. I assume that most people throw these paper bits away in the end I believe that I am not the only person who hopes for a better way of keeping expenditure records. It is believed, the said"new systems platform"will provide a foundation for this change.

Continuing the description of the drawings, in Fig. 2 the critical feature is the delayed application of the received decrypted data Di via the bit propagation delay element 5, in such a manner that the encryption/decryption algorithm 4 is, at one or more points, affected by the stream of the clear data- Exactly the same also happens with the outgoing clear data Do in the bit delay element 6.

For the purpose of presenting the principle of using TEXT as one of the parameters for modifying the interplay of the various logic functions of the algorithm 4, it is not necessary to show a specific example. It is clear that any number of examples could be produced.

Usually, the consecutive logic levels of the bit sequences of the clear text are applied to one of the inputs of an AND-gate, or TREBLE AND-gate, to enable the other input, or respectively the other two inputs, of the gate when the text bit is high, and to disable them when the text input is low. More involved enable inputs are also possible, and a text bit can affect more than one functional element of the algorithm 4.

The delays produced by units 5 and 6 are measured in clock pulses.

The delay units 5 and 6 may each be provided with a manually pre-settable adjustment of the number of clock pulse delays. In a public system, it is clear that the delays must consistently be the same for a long period, say one year, since the change of the delay setting would produce also a change in the encrypted text configuration. The usefulness of a once a year alteration of the delay setting might be to force the owners of cards or card token devices to have their cards handed to the banks for re-adjustment-On that occasion, all the card data are checked and technical criteria of a good device are approved. Those which fall below spec are replaced.

The delay figure for the delay elements 5 and 6 need not necessarily be the same.

In a non-public system, say in communication between two internet stations, the setting of the delays would be equivalent to the setting of a pass word. Only the stations using the same'pass word'will generate a legible text for the conversation partner.

Claims

C I a i m s 1. A fare collection and general Payment System composed of inter-related components, namely (a) an identifiable personal payment token device capable of electronically storing independently from each other a cash value reserve, a value reserve debited to an account, and a value reserve credited to an account.

(b) at least one public transport provider unit organised to be responsive to a demand for transport from the general public in terms of a coded starting point and a coded arrival point, after having these and other parameters down-loaded into the said pay token device in return for a verified payment made from said device to said transport provider or his agent.

(c) at least one product provider unit or retail trader selling goods and articles to the general public in return for a commensurate electronic payment from said pay token device to said Product Provider, said system being characterised by the employment of mobile phone transmission techniques for the sending and receiving of rule-related and security-related data such as: encryption keys, the account numbers of closed accounts, and the serial or account numbers of those said payment token devices that had received value- added updates entered by a Service Provider.
2. The fare collection and General Payment System of Claim 1, wherein the Service Providers are equipped with automatic value-add terminals capable of sensing when after deduction of a purchase price the device value would become negative, and of adding a fixed value, approved by the issuing bank and read from said payment token device, so as to allow the intended transaction to proceed while delivering to a register of said terminal the identifying particulars of the said payment token device, for subsequent transmission to the Issuer of said device.

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3. A fare collection and general payment system composed of inter-related components as claimed in Claims 1 and 2, said system comprising a piece of equipment capable of generating random or pseudo-random numbers, each such number being associated with an access code wherein the access code is always transmitted in the clear, the random number always in its encrypted form.
4. A fare collection and general payment system as in Claims 1 and 3, w h e r e i n the said random numbers are used as encryption keys, with these keys being stored within the said payment token device together with its access code, and wherein the key replacement routine is characterised by the following consecutive steps Upon presentation of the card to the Reader, the coded access code is entered into the transaction device Encryption of the said key number by itself Receiving the said encrypted key number by the transaction device with its record within the transaction device being accessed on the basis of the also received clear address code, and comparing it with the decrypted number if correct as it normally will be, the new random number generated by the said key number generator is encrypted with the old key as presented by said payment device; the encrypted new key number is decrypted within the pay- ment device and entered into the key register of the said payment device, and after this step the old key is abandoned within the said payment token device.
5. A fare collection and General Payment Systems as in Claim 1, wherein the coded arrival point is delivered at a point of exit at the time when the exit Reader is instructed by said payment token device to do so, and the fare is debited to said device.

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6. A fare collection and general payment system as in Claim 1 wherein the integrated processor IC comprises an algorithm for controlling the encryption functions.
7. A fare collection and general payment System as in Claims 1 & 6, wherein the said algorithm comprises a number of logical functions which interact, resulting in the encrypted text at the algorithm output point.
8. A fare collection and General Payment System as in Claims 1 and 6 characterised by the clear texts being applied to selected points of the algorithm functions via Enable Gates in such a manner that the said clear data text thereby modifies the end effect of the algorithm functions.
9. A fare collection and General Payment System as in Claim 8 wherein the logic bit levels are applied to the algorithm via a time delay link with delays being defined in terms of clock pulse intervals.
10. A fare collection and general payment system as in Claims 1 and 8, wherein the delay link between the instant text bit in- put and its output has means for manually pre-setting the delay in terms of a number of clock pulses of the systems clock.