Edward J Richter

US Patent:

7210627, May 1, 2007

Filed:

Dec 17, 2004

Appl. No.:

11/014931

Inventors:

Edward J. Richter - Richmond Heights MO, US
George L. Engel - Maryville IL, US

International Classification:

G06K 7/08

US Classification:

235449

Abstract:

A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. One embodiment of the invention includes an over-sampled modulator and at least one channel in communication with an output of the over-sampled modulator. The at least one channel is configured to filter the output of the over-sampled modulator and the at least one channel is configured to vary the bandwidth of the filter applied to the output of the over-sampled modulator in response to variations in the bandwidth of the signal generated by the sensing unit.

US Patent:

7377433, May 27, 2008

Filed:

Dec 17, 2004

Appl. No.:

11/015271

Inventors:

Edward J. Richter - Richmond Heights MO, US
George L. Engel - Maryville IL, US

Assignee:

Washington University in St. Louis - St. Louis MO

International Classification:

G06K 7/08

US Classification:

235449, 235493

Abstract:

A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. In one embodiment, the invention includes a sensing unit configured to generate a signal indicative of the sensed magnetic field and an amplifier. The amplifier is in communication with the sensing unit, is configured to amplify signals having amplitudes less than a threshold by at least a first factor and configured to amplify signals having amplitudes greater than the threshold by at most a second factor. The first factor is greater than the second factor. The invention also includes an analog-to-digital converter (ADC) in communication with the amplifier and configured to digitize the analog signal, a filter in communication with the ADC configured to attenuate the portion of the digitized signal indicative of the stored data, a data extraction unit in communication with the ADC and the filter, which is configured to measure bit duration and peak location and an authentication extraction unit in communication with the filter and the data extraction unit, which is configured to extract a set of scaled samples representative of the remanent noise characteristic.