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BACKGROUND OF INVENTION
This invention relates to a method and apparatus for storing information
corresponding to personal identification features on a portable storage
medium and reading the information from the portable storage medium to
verify a person's identity.
The use of credit cards and charge plates requires a means of positive
identification which will prevent counterfeiting. In addition, the
necessity of identifying persons for access to secured areas requires
positive identification to prevent impersonation. Personal recognition is
the ideal method of identification, but it is impractical except in a few
situations.
An automatic personal verifier system described in U.S. Pat. No. 3,781,113,
comprises a coherent optical matched-filter corrolator. It computes the
two dimensional cross corrolation function between the present fingerprint
and a fingerprint previously encoded on an identification card. If these
fingerprints match, a bright spot of light is generated at the output of
the optical system. If the prints fail to match, a random low-intensity
light pattern is generated. Whenever the corrolated peak exceeds a preset
threshold, a green light is turned on and a relay is closed. The relay
closure is typically used to energize a door-lock solenoid. Each
identification card in the automatic personal verifier system contains a
small photographic film chip. The image recorded on this film chip is a
coded version of the bearer's fingerprint. Any person seeking entrance to
a facility protected by this automatic personal verifier system must
deposit a fresh oil fingerprint on a special window. As previously
mentioned, the system corrolates the fresh fingerprint with the stored
fingerprint. If they match a green light is energized and the door is
unlatched.
Although the system described in U.S. Pat. No. 3,781,113 provides some
level of security, each person using the system and having the associated
apparatus including the key to descramble the information fixed on the
identification card, can read any confidential information stored on every
identification card.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a method
and apparatus for personal identification which can not be circumvented by
unauthorized persons.
It is a further object of the present invention to provide a method and
apparatus for a personal authentication system in which scrambled
information corresponding to the user's personal features are stored on a
portable storage medium.
It is a further object of the present invention to provide a method and
apparatus for a personal authentication system in which the portable
storage medium can be used to verify the identity of a person. The present
invention provides a personal authentication system in which scrambled
information corresponding to a person's personal features is stored on a
portable storage medium. To accomplish this storage the personal features
of a person are first sensed. Then information signals corresponding to
the sensed personal features are derived and a characteristic scramble key
is developed from the information signals. This scramble key is used to
encode the information signals which are then stored on the portable
storage medium.
The invention further provides a method and apparatus for verifying the
identity of a person using a portable storage medium on which encoded
personal identification information signals have been stored. The personal
features of the person to be identified are sensed and present information
signals corresponding to the sensed features are derived. Then a
characteristic scramble key is developed from the present information
signals and a first set of comparison encoded information signals stored
on the portable storage medium are sensed and decoded with the
characteristic scramble key developed from the present information
signals. A second set of comparison signals are derived from the decoded
information signals and compared to the first set of comparison signals to
verify identity of the person.
Development of a characteristic scramble key from the personal features of
the person seeking access and use of this scramble key for encoding and
decoding purposes prevents unauthorized access to a protected facility.
Theft of the apparatus which provides the scramble key only enables the
person to read his personal identification card. Therefore, other
identification cards cannot be read nor can access be gained by using
identification cards belonging to other people.
This invention can utilize, for example, personal features such as
fingerprints, speech and faces. In addition holograms, scrambled magnetic
recording systems or a light modulating system can be used.
Other features and advantages of the invention will be apparent from the
following description of the preferred embodiments, and from the claims.
For a full understanding of the present invention, reference should now be
made to the following detailed description of preferred embodiments of the
invention and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation, partly in section, of apparatus for
generating and storing scrambled information, corresponding to a personal
feature, on a portable storage medium, wherein the personal features are
derived from fingerprints and the storage medium is an identification card
being made comprising a hologram.
FIG. 2 is a schematic representation, partly in section, of apparatus for
verifying the identity of a person using an identification card made in
accordance with FIG. 1 on which encoded personal identification
information signals derived from fingerprints have been stored by means of
a hologram.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention will now be described with
reference to FIGS. 1 and 2 of the drawings.
Referring to FIG. 1, the apparatus for storing information uses a basic
coherent light input in the form of a laser 1, which directs light beam 2
to beam splitter 3 and also to slide 4 which has on it a photograph of the
fingerprint to be used in generating the holographic image stored on
identification card 5. The beam splitter 3 directs reference laser beam 6
to mirror 7 and then to encoder 8 which will be described in more detail
below.
The reference beam passing through encoder 8 impinges on card 5
superimposing the object beam 11, focused by lens 9, and creating a
hologram. A sensitive film 10 is placed on card 5 and when the subject's
fingerprint has been placed, by means of slide 4, within the object beam a
holographic exposure is made with reference beam 6 and object beam 11. The
lens is focused to provide real image 12 of the fingerprint slide a
distance behind card 5.
To modulate or encode the reference laser beam 6, detector 14 detects
personal features from a present fingerprint 15 of the subject to the
identified. Detector 14, coupled to sensor 13, derives information signals
corresponding to the sensed present fingerprint 15 and delivers these
signals to am image processing system 16. A typical image processing
system including a sensor, detector, and image processor is described in
U.S. Pat. No. 4,340,300 issued July 20, 1982 to by the same inventor.
The image processing system creates a code word 17 based on the fingerprint
features which consists of a sequence of binary digits that describes the
features of the fingerprint according to rules used for fingerprint
detection described in `The LX39 Latent Fingerprint Matcher'`, NBS Special
Publication 500-36 issued August 1978 and in `Manual and Automated
Fingerprint Registration`, NBS Technical Note 730 issued June 1972 and
`The M40 Fingerprint Matcher`, Technical Note 878, 1972.
The code word represents a scramble key and is fed to an encoder 8 which
includes an electronic decoder 18 and a mechanical device. The mechanical
device comprises a coded aperture 19, consisting of a plate carrying an
aperture of any shape whereby the plate can be moved in the x, y, or z
directions, according to the coordinate axes, by electromotive means. The
coded aperture, placed between the reference laser beam and the
identification card, modulates the reference laser beam. The laser beam is
then dispersed by dispersing unit 20 which consists of ground glass. The
encoder, typically referred to as a general optical element, changes the
phase and/or amplitude of the laser beam passing through it. If the coded
aperture is used as a reflecting element the laser beam is reflected by
that element randomly.
The coded aperture 19, mechanically moved in three directions including
circular movement by the encoder, acts as a means for scrambling the
reference laser beam, to create a scrambled hologram for use on the
identification card. The scrambling depends on the fingerprint of the
person to be registered.
It is also possible to use an electronically controlled decoder or an
electro-optical pattern generator such as described, for example, in
"Laser Focus", June 1979, page 85 or "Titus-device", IEEE Transactions on
Computers, Vol. C24, No. 3, April 1975, page 393, in place of the
mechanical encoder.
The identification card now carries a photograph of an encoded hologram of
the persons fingerprint on film 10, which is encoded by a scramble key
derived from the present fingerprint 15.
Referring to FIG. 2, the use of card 5 in a personal authentication system
will be described. Any person entering facilities secured by the personal
authenication system according to the invention, inserts his
identification card, which carries his encoded fingerprint hologram into a
decoding apparatus. At substantially the same time he must deposit a fresh
fingerprint 15 on sensor 13, coupled to detector 14, which senses the
fingerprint and derives present information signals corresponding to the
sensed fingerprint. The image processing system 16 coupled to detector 14,
develops a characteristic code word 17 which represents a scramble key as
previously described. The code word 17 is delivered to decoder unit 21
which operates and is designed as already described. The encoder moves
coded aperture 19 by mechanical means according to code word 17. Thereby,
reference laser beam 6 is shaped by the coded aperture 19 in the same way
as it is modulated during the production of the identification card. The
reference laser beam them impinges on the ground glass dispersing unit 20
to create a dispersed reference laser beam 28.
To decode the hologram on film 10, card 5 is lighted by the dispersed and
shaped or modulated demodulated reference laser beam 28, and a decoded
real image 12 of the fingerprint is projected onto a photo-optical sensor
22. The sensor 22 is located the same distance from the card as the real
image of the fingerprint is located from the card shown in FIG. 1. This
represents an integral part of the sensor-detector system used for
developing information signals. In other words, the decoder unit 21 serves
to unscramble the holographic image stored on film 10 to provide a code
word derived from the decoded real image from the stored image which
corresponds to codeword being generated directly from finger 15.
A second image processing system 23, which operates and is designed
according to image processing system 16, which has already been discussed,
develops a second code word 24 based on the decoded image projected on the
sensor. This code word consists of a series of binary digits.
A comparator 25 coupled to the imaging processing system 16 of the present
fingerprint and to the second image processing system 23 of the decoded
fingerprint compares both code words. If the code word 17 derived from the
present fingerprint matches the code word 24 derived from the stored and
decoded fingerprint, a light 26 is energized and door 27 is unlocked.
There has thus been shown and described novel apparatus for producing a
Personal Authentication System which fulfills all the objects and
advantages sought therefore. Many changes, modifications, variations and
other uses and applications of the subject invention will, however, become
apparent to those skilled in the art after considering this specification
and the accompanying drawings which disclose preferred embodiments
thereof. All such changes, modifications, variations and other uses and
applications which do not depart from the spirit and scope of the
invention are deemed to be covered by the invention which is limited only
by the claims which follow.
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