Abstract: A method for permitting the secure handling of data between two remote stations firstly involves the generation of an encrypted decryption key which is based on a fingerprint information signal from a user of a first station, a fingerprint information signal from a user of a second station, and a key representing function derived from a random key. The encrypted decryption key is of the type with the property that when it is written to a spatial light modulator (SLM) of an optical correlator, the output of the correlator is similar when input with either one of the fingerprint information signals. The encrypted key is then stored at both stations. Thereafter a message encrypted with the key may be decrypted at either station by retrieving the encrypted key, writing the encrypted key to a filter of an optical correlator, inputting one of the fingerprint information signals to the correlator in order to allow recovery of the decryption key, and applying the decryption key to the encrypted message.

Abstract: A public key cryptographic system is implemented as follows. In an enrolment apparatus, the unique number for use in generating the public key and private key of the system is generated by manipulation of fingerprint information of a subscriber. A filter is then generated which is a function both of the Fourier transform of the subscriber's fingerprint(s) and of the unique number. This filter is stored on a subscriber card. When the subscriber wishes to generate his public or private key, he inputs his card to a card reader of an apparatus and places his finger(s) on a fingerprint input. The apparatus generates an optical Fourier transform from the fingerprint input. The Fourier transform signal is incident on to a spatial light modulator programmed with the filter information from the card. An inverse transform is generated from the filtered signal and this is used to regenerate the unique number. The apparatus also has a subsystem for utilizing the private key to decrypt an input encrypted message.

Abstract: A person wanting an entitlement, such as welfare, typically inputs his fingerprint to a database. On a match with a fingerprint already in the database, a profile of the person with the matching fingerprint is retrieved to guard against double dipping. There is a concern for the privacy of the information in the database. To assure privacy, the profile associated with each fingerprint in the database is encrypted so that when a new person attempts to enroll and a matching fingerprint is found in the database, the associated profile returned is encrypted. In order to access this encrypted profile, PINs are required from one or two authorized operators. The PIN of an authorized operator is stored on a card in an encrypted fashion such that it may be recovered by the authorized operator inputting his fingerprint to the system. One or both PINs are needed to decipher the profile.

Abstract: A hybrid optical-digital technique is provided for automatic fingerprint verification. A coherent optical beam modulated with the characteristics of a fingerprint image passes through the lens performing an optical Fourier transform. The intensity array that represents the Fourier power spectrum is recorded and processed. In enrolment, several arrays related to the same finger are captured and processed. A template which is unique for each fingerprint is generated and stored. Using the set of arrays captured in enrolment and a set of templates from a standard database, the processor calculates dependences of false rejection rate and false acceptance rate upon a metric of comparison. The metric is obtained by calculating a relative distance between two arrays in Hilbert space. An individual threshold of verification for a person to be enroled is set and stored together with the template.

Abstract: A method using a fingerprint image as a cipher for optical encrypting and decrypting information which is presented in the form of an analogous signal. The method includes recording a Fourier hologram, the complex amplitude of the spatial grating of the hologram being a Fourier transform of the information image divided by a Fourier transform of the fingerprint image. To prepare the hologram, a full-complex spatial light modulator (SLM) may be used. The parameters of the Fourier transforms are chosen such that the optical spatial frequencies of the information image and the cipher lie in the same physical range. In another embodiment, the intensity distribution of the Fourier spectrum of the fingerprint image is captured. The cipher image is obtained by illuminating a phase-only SLM which is addressed with a function derived from this intensity distribution. The hologram may be amplitude or phase; thin, thick or volume; transparent or reflective; prepared optically or computer-generated.

Abstract: A method for permitting the secure handling or data between two remote stations firstly involves the generation of an encrypted decryption key which is based on a fingerprint information signal from a user of a first station, a fingerprint information signal from a user of a second station, and a key representing function derived from a random key. The encrypted decryption key is of the type with the property that when it is written to a spatial light modulator (SLM) of an optical correlator, the output of the correlator is similar when input with either one of the fingerprint information signals. The encrypted key is then stored at both stations. Thereafter a message encrypted with the key may be decrypted at either station by retrieving the encrypted key, writing the encrypted key to a filter of an optical correlator, inputting one of the fingerprint information signals to the correlator in order to allow recovery of the decryption key, and applying the decryption key to the encrypted message.

Abstract: A method and apparatus using biometric information (such as a fingerprint, an iris structure, etc.) as a cipher for encrypting and decrypting a personal identification number (PIN) which is used as an input to a PIN requiring device. The method of encryption of a PIN includes generating a sequence of random characters representing a PIN to be encrypted; obtaining a generating function such that the random characters are coefficients in an expansion of a square of said generating function over basis functions; and dividing a transform of the generating function by Fourier transformed information image signal to obtain the encrypted PIN. The latter is stored digitally or as a hologram in a personal card or a database. To decrypt the PIN, a full-complex spatial light modulator is illuminated with an optical beam carrying the Fourier transform of the biometric image of an individual to be identified.

Abstract: A key generation system is implemented as follows. In an enrolment apparatus, a unique number for use with PIN operated machines or public key cryptography systems is generated by manipulation of fingerprint information of a subscriber. A filter is then generated which is a function both of the Fourier transform of the subscriber's fingerprint(s) and of the unique number. This filter is stored on a subscriber card. When the subscriber wishes to generate his key, he inputs his card to a card reader of an apparatus and places his finger(s) on a fingerprint input. The apparatus generates an optical Fourier transform from the fingerprint input. The Fourier transform signal is incident on to a spatial light modulator programmed with the filter information from the card. An inverse transform is generated from the filtered signal and this is used to regenerate the key that will be used as the PIN in a PIN operated device, or as the private key cryptography system.

Abstract: A public key cryptographic system is implemented as follows. In an enrolment apparatus, the unique number for use in generating the public key and private key of the system is generated by manipulation of fingerprint information of a subscriber. A filter is then generated which is a function both of the Fourier transform of the subscriber's fingerprint(s) and of the unique number. This filter is stored on a subscriber card. When the subscriber wishes to generate his public or private key, he inputs his card to a card reader of an apparatus and places his finger(s) on a fingerprint input. The apparatus generates an optical Fourier transform from the fingerprint input. The Fourier transform signal is incident on to a spatial light modulator programmed with the filter information from the card. An inverse transform is generated from the filtered signal and this is used to regenerate the unique number. The apparatus also has a subsystem for utilizing the private key to decrypt an input encrypted message.

Abstract: The invention relates to an optical processing fingerprint verification device. A light source illuminates a prism upon which the user has placed two fingers to that light reflected from the prism is modulated by the data of the users fingerprints. The fingerprint data beam passes through a lens and undergoes a Fourier transform at a card including a reflection hologram matched to two fingerprints of a reference individual. The intensity distribution of the ligh reflected from the hologram determines whether a match exists. Use of a reflection hologram allows use of an incoherent light source. The two fingers are located on the prism by movable guides positioned by information on the card as to the relative length and the width of the two fingers of the reference individual. This provides a second level of verification. Scaling sensitivity may be reduced by utilizing a frequency multiplexed hologram.