Patent ID: 7013030

Claim:
A biometric method of authenticating the identity of an individual employing a preselected sequence of linear partial fingerprint signatures processed in the frequency domain, comprising the steps of: (a) obtaining a reference set of linear partial fingerprint signatures from an individual and electronically performing a Fourier transform on said reference set to obtain a frequency domain reference set; (b) storing a first electronic representation of said reference set in a comparison means, said first electronic representation selected from a group including said reference set and said frequency domain reference set; (c) generating a candidate set of linear partial fingerprint signatures from an individual and electronically performing a Fourier transform on said candidate set to obtain a frequency domain candidate set; (d) entering a second electronic representation of said candidate set into said comparison means, said second electronic representation selected from a group including said candidate set and said frequency domain candidate set; (e) providing a comparison means for comparing said first and second electronic representations and (f) calculating in said comparison means a dot product of said frequency domain reference set with the complex conjugate of said frequency domain candidate set, or alternately, a dot product of said frequency domain candidate set with the complex conjugate of said frequency domain reference set; and (g) formulating a similarity index from said dot product calculation, said similarity index resulting in the production of a real number between 0 and 1 resulting from said formulating, whereby the identity of an individual providing said reference and candidate sets may be authenticated if said similarity index is greater than a predetermined level between 0 and 1.