Note: Descriptions are shown in the official language in which they were submitted.
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Backqround and Summary of the Invention
Certain known security systems rely on the most
sophisticated memory system available, i.e., the human brain, to
secure digital data against unauthorized use or manipulation.
Systems of this type accept account codes and also secret codes
from an individual for encoding in accordance with a coding scheme
that is controlled by such code words to yield a compiled code
word of fixed word length despite the length of the applied
code words (see, for example, U. S. Patent No~ 3,938,091, entitled
"Personal Yerification System", issued on February 10, 1976~.
One difficulty encountered in a security system of this type is
that a vast number of institùtions relying in common upon such
security systems require additional security against possible
interactions of such encoded data between institutions, or be-
tween different stations within an institution.
Accordingly, in accordance with a preferred embodiment
of the present itlvention~ an additional control word is applied
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to the encoding logic to establish a unique encryption scheme for
a given institution, or at a given secured location which is a
function of the control word. Thus, a large number of the order
of one billion distinctive encryption schemes may be provided for
operation on a comparably large number of different combinations
of code words that may possibly be applied thereto.
In accordance with one aspect of this invention there is
provided the method of operating a personal verification system
including encoding means having an input for receiving a control
code input representative of the location, and a code word input
means coupled to the encoding means and operable for verifying
the authority of an individual to complete transactions on the
basis of the combination of an individual code word which is
peculiar to the individual, a secret code word which need only be
known to the individual, a control code representative of the
location, and a compiled code word which is derived from the other
of the code words ! the method comprising the steps, performed in
selected sequence, of:
preparing a logical encoding status at the location in
accordance with a selected logical combination of the control code
for the location, the individual code word and a secret code word
received from the individual prior to verification of his authority
to complete a transaction;
encoding the combination of the control code for the
location, the individual code word and the secret code word re-
ceived from the individual by logically combining the control code
for the location and the secret code word received from the
individual to produce an encrypted control code, and by encoding
the combination of the encrypted control code, the individual code
word and the secret code word received from the individual in
accordance with said logical encoding status to produce a compiled
~:~ code word therefrom;
preparing a record of said compiled code word for subsequent
: use in verifying the authority of the individual to complete a
transaction;
applying to the code word input means of the system both
an individual code word for identifying the individual attempting
to complete a transaction and a secret code word from such
individual;
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preparing a logical encoding status in the encoding means
of the s~stem in accordance with said logical combination of the
control code for the location, the individual code word and secret
code word applied to the code word input means of the system;
encoding the combination of the control code for the
location, the individual code word and the secret code word applied
to the code word input means by logically combining the control
code for the location and the secret code word received from the
individual to produce an encrypted control code, and by encoding
the combination of the encrypted control code, the individual code
word and the secret code word received from the individual in
accordance with said logical encoding status prepared in the en-
coding means of the system to produce a corresponding compiled code
word therefrom;
comparing said corresponding compiled code word with the
compiled code word from said record for the authorized indi.vidual
having such individual code word; and
controlling completion of the transaction in response to
the comparison of the compiled code word from said record with said
corresponding compiled code word produced from the control code for
the location, the applied individual code word and secret code word
received from the indi~idual attempting to complete the transaction.
In accordance with another aspect of this invention there
is provided apparatus for verifying the authority of an individual
~5 to complete a transaction on the basis of logical manipulation of
a control code word indicative of an encoding location, an indiv-
idual's identifying code word, his secret code word and an encoded
word logically derived from such code words, the apparatus com-
prising:
encoding means providing a variable encoding operation
which is a function of the logical combination of all code words
applied thereto for producing an encoded word therefrom in
accordance with said encoding operation which is also determined
by said secret code word;
auxiliary encoding means coupled to receive the control
code word and the individual's secret code word for producing an
encrypted control code word in accordance with a logical combination
thereof for application to said encoding means;
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input means coupled to said encoding means for applying
thereto an individual's identifying code word and the individual's
secret code word for providing said encoding operation therefrom in
accordance with said logical combination of the encrypted control
code word, the individual's identifying code word and secret code
word, said encoding means producing said encoded word for the
individual in an initial transaction in accordance with said en-
coding operation from the encrypted control code word, the applied
individual's identifying code word and secret code word;
said encoding means also providing an encoded word in a
subsequent transaction by encoding the combination of the encrypted
control code word, the authorized individual's identifying code
word and secret code word in accordance with a variable encoding
operation which is determined by said logical combination of the
encrypted control code word, the authorized individual's identify-
ing code word and secret code word; and
means for comparing said encoded word prepared for the
authorized individual in the initial transaction with said encoded
word produced during the course of a subsequent transaction to com-
plete the transaction with respect to said individual's identifyingcode word in response to comparison of said encoded words.
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Descr ption of the~ Drawings
Figure 1 is a logic flow chaxt illustrating the
operation of the present invention;
Figure 2 is a logic flow chart illustrating the
operation of another embodiment of the present invention;
and
Figure 3 is a schematic diagram of one circuit
embodiment according to the present invention.
Description of the Preferred Embodiment
In addition, with reference to Figures 1 and 2
hereof, there are shown logic flow charts that illustrate
the inter-relationships between the various code word
inputs in the operation of the present invention. In one
embodiment the identifying code word (e.g., social
security number, account number, driver's license number,
etc., or combinations thereof) for an individual may be
entered using a suitable code word entry means 31 such as
a keyboard, a card reader, or the like. Similarly, a
secret code word for the individual may be entered by the
individual using the same or another suitable code word
entry means 33 of the type discussed above.
These code words are converted to digital
signals which may or may not be buffered or temporarily
stored 35 for application to the encoder 37 in a selected
order, independently
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of the order in which the code words are received from the
individual.
In accordance with the present invention, the encoding
of an individual's own identifying code and his secret code in
S accordance with an encoding scheme is further altered or deter-
mined by the introduction of a control code word 39 which may be
unique to the particular institution, or which may be unique to
a particular data terminal in an institution. The encoder output
is a compiled code word which may be of ixed word length (e.g.,
always digits~ independently of the length of the entered code
words 31, 33). This compiled code word may thereafter be re-
corded for subsequent retrieval and comparison with a compiled
code word prepared in the same manner for an individual who
attempts to complete a transaction that is secured by the present
lS invention. Alternatively, the compiled code word may be con-
sidered as data and transmitted along with other data (e.g. 7
inventory numbers, price information, etc.) for remote processing.
Referring now to Figure 3, there is shown a simplified
schematic diagram of one e~bodiment of the present invention in
which the identifying code word and the secret code word for an
individual are entered in selected order using the same manual
keyboard entry means 2. The individual keys 11 of the keyboard 2
are individually connectable to a grounded bus 12 by depressing
or actuating the key. One output from each of the keys 11 is
fed to the corresponding input of a NAND gate 13 for generating
an output which triggers a one-shot 14 to produce a negative pulse
Oll line 15. Each of the individual keys 11 is also connected to
a corresponding input of a 12-bit latch 16, such 12-bit latch 16
being formed~ for example, by three Model 9322 integrated circuitsO
Thus, whenever a key 11 is depressed, one of the lines connected
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with the key provides a 0 (low) signal to both the 12-bit
latch 16 and the NAND date 13.
The output of the NAND gate 13 fires the one-shot 14 to
generate a negative-going pulse to the parallel enable input 15
of a 12-bit UP binary counter 17 to load the 12-bit latch 16
contents into the 12-bit UP binary counter 17. Initially, the
12-bit UP binary counter 17 is resting at an all 1 state, i.e.,
the terminal coun~ output is a "high" which when inverted through
an inverter 18 provides a "low" to the count enable pulse input
terminal of the 12-bit binary counter i7 to disable the binary
counter 17. The binary counter 17 comprises, for examplet three
Model 9316 integrated circuits.
As soon as a key 11 is depressed, a set of twelve bits
is loaded from the latch 16 into the binary counter 17 and the
terminal count on the binary counter 17 drops to a low which
when inverted by inverter 18 produces a high count enable pulse
causing the binary counter 17 to count from the loaded state up
to an all 1 state which makes the terminal count high. The high
is inverted by inverter 18 to a low which disables the binary
counter 17 to terminate the counting function. Thus 7 the output
of the inverter 18 is a high pulse of a duration corresponding to
the time it takes the binary counter 17 to count clock pulses
from the state loaded into the binary counter to a terminal all
1 state~ Thus~ the operating time of the counter 17 is a function
of the bit state loaded into the binary counter 17, which in turn
depends upon which one of the individual keys 11 was depressed.
The output of the inverter 18 is also fed to one input
of a NAND gate 19 to which the output of the clock generator 21
is also connected. Thus, the NAND gate 19 serves to gate the
clock pulses to the input of a 24-bit shift register 22. The
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number of clock pulses which are gated to the shift register 22is dependent upon the duration of the count of the binary counter
17. The 24-bit shift register 22 may comprise, for example, six
Model 9300 inte~rated circuits.
Thus, the NAND gate 13, one-shot 14, latch 16, binary
counter 17, clock generator 21, inverter 18 and gate 19 serve to
form the key-to-clock pulse translator 5 as described above with
re~ard to Figure 2. The output of the key-to-clock pulse trans-
lator 5 is a train of pulses with the number of pulses in each
train corresponding to the particular key actuated on the alpha-
numeric keyboard 2.
A plurality of exclusive OR gates 23 are hard wired
into the 24-bit shift register 22 in the conventional manner to
provide a plurality of feedback paths to the input of the 24~-bit
feedback shift register 22 for pseudo-randomizing the states of
the register 22. The 24-bit shift register 22 is initialized to
an all 0 starting state by applying a reset pulse on input line
43. Additionally, the 2~-bit cells of the shift register 22 may
be selectively preset to initial conditions determined by the
signals on input lines 45 to each bit cell. Thus~ the final
state of the shift register 22, as manifested by the logic states
on the output lines 47 from the bit cells, after all code words
for an individual are entered in succession via keyboard 2 will
be determined by the control code applied to inputs 45. The
output lines 47 may be grouped into any suitable number, K, of
n-bit alphanumeric characters for transmission as data, or for
display or comparison with similar output signals in the manner
described in the aforecited U. S. patent, or the like. The
control code thus greatly expands the combinations of compiled
code words which may be generated as a result of certain code
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words applied to the code entry means. In addition~ the control
code and the associated encoding may be further secured against
unauthorized use by modifying the control code in accordance with
the secret code word received from the individual~ as illustrated
in Figure 2. In this embodiment, the secret code word may be
combined with a control code (for example~ Route and Transit
number for a given bank) to yield an encoded control code word
for application to the input 45 of shift register 22~ as shown
in Figure 3. This encoding of the control code word with the
secret code word may be performed in any suitable manner, for
example~ by arithmetically adding or subtracting~ multiplying or
dividing one nurnber by the other~ or by interdigitizing the
digits of one number with the digits of the other number, or the
like.
Therefore, the security system of the present invention
provides greatly enhanced security for rnany institutions using
similar systems through the selection of their own control codes.
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