US 4,308,522 A · Identity verification apparatus and method

Abstract

A method and apparatus are provided for verifying the identity of a person by establishing and storing a standard vector for said person based upon predetermined characteristics derived from a number of handwriting samples, and then comparing said standard with a vector derived from a corresponding sample of handwriting provided by said person at the time the identity of said person is to be verified. Derivation of the vector is accomplished by digitizing an analog waveform representing forces generated by writing, compressing the digitized information, extracting Haar coefficients and directly observable features from the compressed digital information, and deriving a vector from said Haar coefficients and said directly observable features.

Claims33

Dependent claims

A method for verifying the identity of a person from samples of handwriting comprising the steps of

A. converting forces generated from writing a signature by the person whose signature is to be verified to an electrical signal representative thereof;
B. generating a digital representation of said signal;
C. deriving an information vector from the digital representation of the signature of the person whose identity is to be verified;
D. providing identification indicia assigned to the person whose signature is to be verified;
E. comparing said information vector with a unique reference vector associated with said identification indica provided for said person to derive an error value representing the variance between the two vectors;
F. comparing said derived error value with a unique threshold value associated with the identification indicia provided for said person;
and
G. providing indication of acceptance if the derived error value is less than the unique threshold value and providing indication of rejection if the derived error value is greater than the unique threshold value.

5 more elements

A machine-implemented method for deriving a standard for verifying the identity of a person from handwritten signatures, comprising the steps of

A. providing a plurality of handwriting samples of the same informational content of a person for whom a reference information vector is desired;
B. providing an electrical signal representative of each of said plurality of handwriting samples;
C. deriving an individual signature vector from each one of said plurality of electrical signals;
D. storing said signature vector;
E. computing an average vector from said plurality of individual signature vectors;
F. computing an individual error value for each signature vector based on a comparison of each signature vector with the average vector;
G. computing an average error value using at least some of said individual error values;
H. computing an acceptance error value based upon said average error value;
I. comparing said individual error values with said acceptance error value;
J. discarding any individual signature vector having an error value in excess of the acceptance error value;
K. providing additional handwriting samples for deriving additional individual signature vectors to replace those discarded;
L. computing individual error values for said additional individual signature vectors;
M. comparing said additional individual error values with said acceptance error value and repeating steps A to J inclusive until a predetermined number of acceptable individual signature vectors have been obtained;
N. computing a revised average signature vector from the acceptable individual signature vectors;
O. computing revised individual error values for each acceptable individual signature vector based on a comparison of each revised individual signature vector with the revised average signature vector;
P. computing a threshold value based upon the revised individual error values;
Q. computing a normalizing vector assigning different weights to different aspects of the revised average information vector in accordance with the degrees of consistency of said different aspects in the various individual signature vectors;
R. computing a reference vector based upon the revised average signature vector and the normalizing vector;
and
S. maintaining the threshold value and the reference vector to be utilized jointly as a standard for use in evaluating a vector derived from a handwritten signature of a person whose identity is to be verified.

17 more elements

A machine-implemented method for deriving a standard for verifying the identity of a person from samples of handwriting, comprrising the steps of

A. providing a plurality of handwriting samples of the same informational content of a person for whom a reference information vector is desired;
B. providing an electrical signal representative of each of said plurality of handwriting samples;
C. deriving an individual information vector from each one of said plurality of electrical signals;
D. computing an average information vector from said plurality of individual information vectors;
E. computing individual error values and an average error value indicative of deviation of said individual information vectors from said avverage information vector;
F. computing an acceptance error value based upon said average error value;
G. discarding any individual information vector having an error value in excess of the acceptance error value;
H. providing and testing additional individual information vectors until a predetermined number of acceptable individual information vectors have been obtained;
I. computing a revised average information vector and revised individual error values from the acceptable individual information vectors;
J. computing a threshold value based upon the revised individual error values;
K. computing a normalizing vector which assigns different weights to different aspects of the revised average information vector;
L. computing a reference vector based upon the revised average information vector and the normalizing vector;
and
M. providing a verification standard comprising the threshold value and the reference value to be used jointly in evaluating a vector derived from a handwriting sample of a person whose identity is to be verified.

11 more elements

Apparatus for deriving a standard for verifying the identity of a person from handwritten signatures, comprising

means for deriving an individual signature vector from each one of a plurality of handwriting samples of the same informational content of a person for whom a reference information vector is desired;
means for storing each said signature vector;
means for computing an average vector from said plurality of individual signature vectors;
means for computing an individual error value for each signature vector based on a comparison of each signature vector with the average vector;
means for computing an average error value using at least some of said individual error values;
means for computing an acceptance error value based upon said average error value;
means for comparing said individual error values with said acceptance error value;
means for discarding any individual signature vector having an error value in excess of the acceptance error value;
means for requesting additional handwriting samples for deriving additional individual signature vectors to replace those discarded;
means for computing individual error values for said additional individual signature vectors;
means for comparing said additional individual error values with said acceptance error value;
means for effecting the generation and testing of additional individual signature vectors until a predetermined number of acceptable individual signature vectors have been obtained;
means for computing a revised average signature vector from the acceptable individual signature vectors;
means for computing revised individual error values for each acceptable individual signature vector based on a comparison of each revised individual signature vector with the revised average signature vector;
means for computing a threshold value based upon the revised individual error values;
means for computing a normalizing vector assigning different weights to different aspects of the revised average signature vector in accordance with the degrees of consistency of said different aspects in the various individual signature vectors;
means for computing a reference vector based upon the revised average signature vector and the normalizing vector;
and
means for maintaining the threshold value and the reference value to be utilized jointly as a standard for use in evaluating a vector derived from a handwritten signature of a person whose identity is to be verified.

16 more elements

Apparatus for deriving a standard for verifying the identity of a person from samples of handwriting, comprising

means for deriving an individual information vector from each one of a plurality of handwriting samples of the same informational content of a person for whom a reference information vector is desired;
means for computing an average information vector from said plurality of individual information vectors;
means for computing individual error values and an average error value indicative of deviation of said individual information vectors from said average information vector;
means for computing an acceptance error value based upon said average error value;
means for discarding any individual information vector having an error value in excess of the acceptance error value;
means for providing and testing additional individual information vectors until a predetermined number of acceptable individual information vectors have been obtained;
means for computing a revised average information vector and revised individual error values from the acceptable individual information vectors;
means for computing a threshold value based upon the revised individual error values;
means for computing a normalizing vector which assigns different weights to different aspects of the revised average information vector;
means for computing a reference vector based upon the revised average information vector and the normalizing vector;
and
means for providing a verification standard comprising the threshold value and the reference to be used jointly in evaluating a vector derived from a handwriting sample of a person whose identity is to be verified.

9 more elements

Dependencies are inferred from the claim text.

Identity verification apparatus and method

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Identity verification apparatus and method

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Abstract

Claims33