Hamburg - Members of the Chaos Computer Club said on Saturday they had copied the thumbprint of German Defence Minister Ursula von der Leyen.
Jan Krissler, speaking in Hamburg at the club's 31st annual convention, said he planned to published an image of the thumbprint soon on the internet.
Krissler said making the copy didn't require an object that von der Leyen's thumb had touched. Instead a commercially available software called VeriFinger was used along with a photograph of her right thumb taken at close range during a news conference in October.
Krissler showed a partial image of the defence minister's thumbprint, saying he was able to complete the missing parts of the image using photographs taken from other angles.
The German news website Zeit Online first reported on research Krissler and fellow hacker Tobias Fiebig have conducted at the Technical University of Berlin into weaknesses in biometric security systems.
It was a repeat of something Krissler did in 2008 when he published a fingerprint belonging to Wolfgang Schaeuble, who was Germany's interior minister at the time.
Biometrics that require a user's fingerprint or an iris scan are being used more and more in security systems. Krissler has shown how many of these systems can be outsmarted.
One example is a facial recognition device that is fooled by a photograph of the person's face. Another is a fake fingerprint that Kissler says can dupe the iPhone fingerprint sensor. - Sapa-dpa