Fingerprint forgery--a survey

The article describes and analyzes the international survey of fingerprint and laboratory personnel about fingerprint forgery, conducted in four countries during the years 1998 through 1999. The awareness and the attitude of the professionals to the problem of fingerprint forgery was tested.     

Dynamic of the ageing of ballpoint pen inks: quantification of phenoxyethanol by GC-MS.

The ageing process of some inks were studied to evaluate whether it is possible to date them. We used gas chromatography coupled with mass spectrometry to measure the evaporation of volatile components. The selected approach thus follows the disappearance of one ink volatile component (phenoxyethanol) as a function of time. The ink ageing curve represents the ratio of an evaporating compound to a stable compound of ink according to time. The results obtained are thus independent of the quantity of ink sampled for analysis. We obtained for two pens, containing two different inks, a curve highlighting an exponential decrease of the evaporating compound. By fitting these curves we determined the limitations of dating a ballpoint pen ink. Two distinct behaviours were observed in two distinct modes, the first called 'fast mode' and the second called 'slow mode'. In order to try to explain the phenomenon, the studies were based on solvent diffusion theory in complex matrix (such as polymer on varnish). Calculations from certain parameters showed an extremely fast evaporation of ink solvents, as well as varying behaviour depending on the paper used. The results showed that it is not possible to date ballpoint pen inks with this method in document examination casework.     

Vulnerabilities of fingerprint reader to fake fingerprints attacks

The purpose of this research is to assess the vulnerabilities of a high resolution fingerprint sensor when confronted with fake fingerprints. The study has not been focused on the decision outcome of the biometric device, but essentially on the scores obtained following the comparison between a query (genuine or fake) and a template using an AFIS system. To do this, fake fingerprints of 12 subjects have been produced with and without their cooperation. These fake fingerprints have been used alongside with real fingers. The study led to three major observations: First, genuine fingerprints produced scores higher than fake fingers (translating a closer proximity) and this tendency is observed considering each subject separately. Second, scores are however not sufficient as a single measure to differentiate these samples (fake from genuine) given the variation due to the donors themselves. That explains why fingerprint readers without vitality detection can be fooled. Third, production methods and subjects greatly influence the scores obtained for fake fingerprints.