Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This invention relates to an electronlc fund transfer
and data protection system.
U.K. Patent publication No. 2,057,740 entitled Security
Arrangements in Data Transfer Equipment, published April 1, 19~1
describes an arran~ement for ensuring -tha-t data contained in
a data storage station cannot be read out without the station
first passing a question-and-answer -test, which is of such a
kind that stereotype (that is forgeable) test answers cannot be
given by the storage station is known. A safeguard against the
possibility of a set of test numbers becoming known, for example,
through unauthorized manipulation of the equipment, is also
described. The relationship be-tween test number storage addres-
ses and the test numbers is changed, and entirely new test numbers
are procured at regular or irregular intervals of time. The
description refers to a cyclic change in the significance of the
numbers, which are initially active, then "semi-retired" and then
vacated numbers. Vacated numbers are always replaced by new
"active" numbers. These test numbers, originating from a single
centralized headquarters of a bank, or of a central clearing bank,
and transmitted from there via scrambled dedicated data lines to
the branches of banks, credit institutes, etc., mainly during
night times, are very safe from unauthorized inspection or inter-
ference, especially if the security measures described hereunder
are applied.
In U.K. Patent publication No. 2,057,7~0 a method of
changing test nurnbers without losing region or nationwide validi-
ty at transaction stations is described. The description relating
to the da-ta transFer bel:ween a portable ~ata token and a trans-
action station is Fairly complete. The precise security measures
required to insure that only an authorized station is able to
change the test codes and that the transfer of transaction data
to another data station is dependent on the fulfillment of
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certain test conditions are not clescr-ibed in cle-tail. An lnvesti-
gation of the overall requirement shows that the concept oF a
self-repairing security system For the data transfer between a
widely dis-tributed pay token and point-of-sale or transaction
terminals has also to be applied to the data communication between
a transaction terminal and a bank or credit card branch, and again
to the communication of test numbers from the clearing center or
bank headquarters from and to the branches. This implies an
hierarchical arrangement For the passing on of periodically
changing test data in the context of an unpredictable sequence
of right and wrong test numbers.
In order to take account of the requirements of an
overall secure system the circuitry shown in Figure 1 of the cited
patent publication has been improved.
According to the present invention there is provided an
electronic fund transfer and da-ta protection system comprising:
a plurality of pcrtable data carriers; a plurality of transaction
terminals; self-contained portable storage units for storing
security test numbers and a list o-f transaction events data ob-
tained from said transaction terminals; computer units with datastorage space for receiving transaction event data from the self-
contained portable storage units and for imparting new test
numbers thereto; and an originating station where security -test
numbers are generate~ and electrically passed to the computer
, units via dedicated communication lines.
The invention wiil now be described in more detail,
by way of example only, with reference to the accompanying
drawings, in which:-
Figure 1 is a block diagram of an electronic fund and
data transfer system similar to Figure 2 of the above-referenced
patent application;
Figure 2 is a more detailed diagram of the system showing
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the improvemen-ts; and
Figure 3 is a survey of the -total sys-tem s-tructure with
respect -to the data flow therein.
In Figure 1 A represents a portable data component
such as described in Figure 1 of -the above-referenced Paten-t
application. The inductive coupling arrangement using coils 2
and 3 and the electrical detail circui-try connec-ted therewith are
described in U.K. Patent Application No. 7,931,208.
The transaction control terminal has corresponding
10 coupling coils 2a for the bidirectional transFer of data and
3a for transferring clock pulses and energy to component A. A
clock phase counter and decoder ~ helps di-fferentiate between
clock pulses having di fferent roles and timing. In conjunction
with a program counter 9 a data multiplex circuit 10 addresses
and activates various portions of the circuit at the required times
and sequences via internal (microelectronic) wires 19, 14, 15, 16,
17, 18, 20, 21, 41 and 43. For example~ the synchronizing pulses
come over wire 41, which ensures that the program counters in
A are synchronized with program counter 9. The address or refer-
20 ence number which originated in token A is passed to the addressdecode unit 30 via wire 19. The selected tes-t number of unit 31,
flanked by one or two wrong test numbers, is clocked out via wire
36 and a current amplifier 6 into the transfer coils 2a, 2 and
circuit A. Similarly, debi t data are transferred via wire 43
! to the data coil 2a. The token circuit's response to the se-
quence of right and wrong test numbers is transmitted via wire
16 -to the response evaluator 33. I f the response shows a faulty
answer the circuit puts an inhibit signal on the oscillator 7
via wire 43 and a~.so produces a faul ty display via wire 35 on
30 the display section 26. Af-ter the token has been tested satis-
factorily the value of the token, or of the selected token account
is read out and shown up in store/display section 22. The debit
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calculator 11 responsive to a debit input 13 calculates the
reduced token or account value and siplays it in section 24.
This display must be in agreement with the subsequent readout of
the new value from the data token 11 directly, as fully described
in the cited patent publication No. 2,057,740. The token is
of course also tested against general qualifying data such as a
code for the national network within which the electronic fund
transfer token has validity or personal membership. This
comparison is carried out by circuit blocks 29 and 29a, and if
this test is negative the intended transation is rejected.
The buffer store 34 contains the new test numbers offer-
ed, for example, via telephone connection to the terminal. This,
however, is by way of indication only. It has always been clear
that security against arbitrary insertion of test data has to be
high, as high as provided for all data exchanges in the system.
Moreover, since the data in memory store 31 constitute variable
data it is necessary to ensure that the functionally associated
circuitry cannot be by-passed. This is best achieved by inte-
grating all the related circuits on a single substrate. These
include at the very least the automatic sequencing changer, the
response evaluator, the address decoder, and all the multiplexing
circuit elements. The transaction memory 63 should be fully
encapsulated conjointly with the integrated circuitry. This leads
to a separation of Fig. 1 into two sections, B and C, the boundary
of B being indicated by the line a - a. This rearrangement is
reflected in the diagram Figure 2. Here, A and B are now repre-
sented by reactively coupled circuit blocks. Again reactively
coupled to this system is now section C in which 31 is the block
of registers for the wrong and right test numbers. (Note, even
the wrong test numbers have address-enable inputs. These, however,
are only used when new test numbers are inserted into block 31 to
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replace "vacated" test numbers. On such occasions even the wrong
numbers are changed at times, for good reason).
Most of the circuit blocks can be recognized as being
in Figure 1. The mul-tiplex circuitry, the program counter, and
the clock phase decoder had to be duplicated, (lOa, 9a and ~a).
For communicating with a data center such as a bank
branch D there are built into block C two further coupling links
2d and 3d which are capable or being coupled ~ith coils 2e and 3e
in unit D. D' represents a MODEM whereby C can communicate wlth
D via a pair of ordinary telephone lines.
The OR gate 54 can accept input data either from coupl-
ing coils 2c or 2d. Similarly 0~ gate 58 accepts clock pulses
either from coil 3d or 3c. Simultaneous inputs are inhibited by
switches 59, 60 and 53.
The transaction memory 63 stores essential information
related to each consecutive transaction individually, such as
Account Number of token owner, bank branch code, date and debit
amount. In order to read out this record from storage unit 63,
certain conditions must be fulfilled. The interrogating computer
unit D will check on the qualifying data held in store 51, which
also aelivers an address number for the first test number held in
store 31. Computer D must then generate the corresponding test
number and transfer it to unit C where it is compared in exclusive
OR gate 61. This is repeated for each of the four test numbers.
If only one is defective, the bistable 62 latches and inhibits
any further processing. This is a safeguard against the transac-
tion memory losing its data through an unwarranted readout. After
the test and readout steps are carried out there remain further
program steps in the program counter. These may be used for pro-
viding a mark to existing active numbers whereby tney are trans-
ferred to the class of semi-retired numbers for vacating another
test number from the last-mentioned group to replace it by an
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entirely new -tes-t number, and fina]ly for changing one or -the
other of the so-called wrong test numbers so as to elimina-te all
~amiliarity elements from the test number structure. As already
indicated, the unit C consists of one or more integrated circuit
chips pot-ted in a fully sealed box. A rechargable battery may
be integral within the device.
As a rule, the unit C is remo~able from its location
within the chassis of unit B, and may be bodily taken to the
trader's own bank branch for the purpose of transferring the in-
formation contained in storage segment 63 to the computer of thebank branch concerned in order to debit the various accounts of
the trader's cus-tomers and to credit the account of the trader
concerned. The fact that this procedure provides the opportunity
for changiny the variable test numbers is an administrative matter
which need not concern the trader.
The transaction list of memory 63 provides space to
register for each transaction the account number of the token,
the debit, a trasaction sequential number, a serial number for
the location of the terminal, and a date. The transaction number
is obtained from the to~en A and represents the number of trans-
actions carried out with the token up to the momen-t before the
next transaction. As the token is checked into sales terminal
this number is incremented by 1 and returned to the token, and
also passed on to unit C to be added to the transaction informa-
tion in store 63.
Figure 2 indicates two stores in the Sales Terminal B,
the just-referred-to store receiving from A the current transac-
tion number and increasing it by 1. The other store holds the
permanent location number identifying the location of the terminal.
These data are passed on to the store 63, but need not necessarily
be repeated here for each transaction although further downstream,
when transaction data are transferred -to the banks' computers,
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-they have to be added together with the time informa-tion. All
these da-ta are needed Eor a certain amount of automa-tic audi-ting
and validity checking in the banks' compu-ters.
The -technlque of the active, semi-active ancl re-tired
test numbers can also be used to pro-tect ~le unalterability of the account number.
This is done by providing in-the token for two accoun-t regis-ters,
one of which holds -the -true accoun-t number whereas the other holds
a func-tion of -the account number ancl the -test number held in the
` -token. A simple case is where -this function is a difference.
If the accoun-t number is called AN and the -tes-t number TN, -the
second account store must hold a number "anJ'=AN - TN irrespective
of sign. When the -token is checked into a point-of-sale terminal
or into an updating terminal bo-th accoun-t numbers are read out
and -the difference formed in an arithme-tic circui-t in the termin-
al must be equal -to TN. If it is not equal the comparator pro-
duces an ou-tput siynal disabling all further opera-tion and pro-
viding a visual indication such as "defective account number" or
'token retained for check-up".
Since, as has been described in the above-referred docu-
ments, -the test numbers change at irregular intervals, the de-
duced AN numbers will also necessarily change over the course of
time. ~ potential forger of the accoun-t number will find himself
rejec-ted, assuminy he may al-together succeed in incorporating a
suitably mul-tiplexed, bu-t nevertheless direc-tly accessable, micro-
store for holding account numbers which he may at will vary.
Since, according to the above defined scheme, i-t is not enough
Eor the would-be forger to generate an account number differen-t
Erorn his own, he must also enter a new AN number which is related
-to the test number held in -the token. This test number~ however,
is so locked into the circuitry that i-t has no ou-tlet to be read
Erom the circuit. ~ot ]cnowing what -this number is, the would-be
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forger cannot thus eEEectively alter the account number of the
token. The only other approach for him would be to -try to moni-
tor, if that were at all possible, and this depends partly on the
detailed techniques employed in tne data transfer, the transfer
means at some point. This would require elaborate apparatus
difficult to place at a publicly accessable terminal. At other
points these data would be completely inaccessable. Nor could
any person be asked what the test numbers are at a given time
since they are electronically random-selected by the head quarters
computer of the clearing house. They are transmitted in scrambl-
ed form to banks and branches all over the country at unpredict-
able dates and times and occupy the system lines for only an
infinitesimal portion o~ their operating times. The token ter-
minals at banks would not permit meddling and would cut even thin
wire probes. Open rapid access terminals would incorporate pre-
cautions against information tapping, and the opportunities for
doing unusual things unobserved would be rare. Whereas one can
never exclude one occasion when all the circumstances happen to
furthex an unobserved fradulent attempt at discovering the test
number, the liklihood that this can be repeated, say week by
week, is virtually non-existent. The risk of being observed
and apprehended would be greater as bank computers would trace
the very first irregularity and also locate the terminal at
which it occured. This would make it too unsafe to repeat illegal
interference, even if possible. The system of variable test num-
bers makes it necessary to monitor them continually.
In summaryl with -the aid of thevariable test numbers
technique a forge attempt directed at the account number of the
pay token can instantly be reEuted and the intended sale stopped.
Figure 3 shows how new test numbers, which originate at
a national bank headquarters or a clearing house center F, are
communicated to regional headquarters ~ , and from there to
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branches D oE the -various banks vla declicated scrambled data
lines. The local bank branches, post offices (giro) and credit
card agencies pass on any new test numbers to -the cumulatlve
transaction box C when checked in physically at their respec-
tive terminals or, via phone lines t. When the box C , as
would normally be the caserforms part of the point~of-sale termin-
als S it passes on to the individual tokens T, when presented to
S, -the new test numbers concerned. While, in theory, it might
be possible to tap the new test signal while it is being trans-
mitted to a data token it is well within the scope of the artto place obstacles in thepath of a person wishing to do that at
a public terminal with fraudulent intent.
The cashless value transfer sys-tem described permits
the use of permanent electronic tokens while maintaining a high
standard of security and versatility. The procurement cost of
the ec~uipment is distributed over several agencies. The tokens,
being permanent, are issued to the public against registration
and an annual membership fee from which the cost of supply and
administration can readily be covered. The box C is purchased
by the individual trading firms. Banks purchase the terminals
and rent them out to traders. Dedica-ted data lines for the trans-
mission of inter-bank data already exist, or will shortly exist.
They will only be lightly loaded by the proposed system.
Thus, for example, in the described system, a pay or
credit card A may be inductively coupled to a data transfer pro-
gramming, processing, and display unit B, which in turn is coupled
via inductive coupling links (2b-2c, 3b-3c~ to a third unit C
consisting of most]y miniaturized circuitry such as storage regis-
ters 31 for two wrong security check numbers and four right num-
bers and auxiliary logic circuitry, and also a transaction listmemory 63. The lat:ter may be constituted as a fully sealed -tape
unit with built-in stepping motor and solid-s-tate comparator
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circui-try. The security check numbers are received and Erom time
-to time updated via inductive coupling lin]cs (2d-2e, 3d~3e) from
a main -transaction office D such as a bank, credit card office,
e-tc. During a card -transaction, responsive to a reference number
emi-tted by the card, one or more of the righ-t numbers and a
wrony number are selected. The automatic sequence chanyer cir-
cuit 32 presents -to the card an unpredictable sequence of the
selected numbers and then -tests -the card reaction to this inpu-t
in a response evaluator circuit 33 . The test and transaction
list unit C is optional at a card terminal and is required
only a-t ofE-line sta-tions (i.e. for smaller -traders and vendiny
machines where separate da-ta lines to banks would not be econorni-
cal). Where on-line operation is possible, the bank computer D
performs the check operations of uni-t C. Accordinyly, the bank
computer D communicates during day time wi-th cards A via pro-
cessors s which belony to on-line terminals, while duriny niyht
time and early morning hours the accummulated off-line transac-
tions are received from the test and -transaction storaye unit C
~ia a MODEM D' , when also the cyclically required modifica-tion
of one of the registers 31 is performed. The ~ank computer D
itself receives from time to time modification instructions for
its security check number register via interbank da-ta lines from
the bank head office. The head offices of different banks receive
similar data from a sinyle random da-ta yenerator or clearing bank
director respectively. A card processor for unpredictable sequenae
of riyh-t and wrony test numbers is here presented as a complete
card da-ta and regional transac-tion transfer security system.
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