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Liveness Detection of a Finger Based on Changes of Papillary Lines
Lichvár, Michal ; Orság, Filip (referee) ; Drahanský, Martin (advisor)
There are several frauds against biometric systems (BSs) and several techniques exist to secure BSs against these frauds. One of the techniques is liveness detection. To fool fingerprint sensors, latent fingerprints, dummy fingers and wafer-thin layer attached to the finger are being used. Liveness detection is being used also when scanning fingerprints. Several different characteristics of the live finger can be used to detect liveness, for example sweat, conductivity etc. In this thesis, new approach is examined. It is based on the expandability of the finger as an effect of heartbeats/pulsation. As the skin is expanding, also the distances between papillary lines are expanding. Whole finger expands approximately in range of 4,5 ľm , the distance between two neighbor papillary lines in 0,454 ľm . This value collides with wavelength of blue and green light. The result from this work is following. The resolution of the capturing device is not high enough to capture the expandability on distance between two neighbor papillary lines. Also, because of collision with wavelength, the diffraction effect is presented and the result images are influenced by this error.
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Design of the laboratory task for attack on fingerprint authentication
Spurný, Jiří ; Vyoral, Josef (referee) ; Burda, Karel (advisor)
This thesis deal with personal fingerprint authentication and contains basic types of fingerprint readers included their principles of working. In this thesis are collected published attempts to this type of biometric authentication and in detail described way, how these attempts were realized . Realization of lab measurement is mentioned in practical part of thesis, is designed based on collected and evaluated information. Tendency for realization was to use materials and procedures which are available on market as well as computer technology. So no special equipment is needed for realization. Practical part describes in detail procedures for papillary lines capturing and their electronic processing. Described is also way to break through optical finger print sensor. For confirmation of procedure was made 12 artificial finger casts from Lukopren material. There casts were used to attempt on optical sensor Microsoft Fingerprint Reader with 100% success. Based on realized tests to produce artificial casts was proposed procedure for realization of laboratory measurement. This procedure is described in main part of this thesis. Proposed procedure has been confirmed in 90 minutes time limit, based on requirement to achieve time limit of school training session.
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