Bochum Researchers (IMAGE) Ruhr-University Bochum Caption Philipp Markert from RUB's Horst Görtz Institute for IT-Security (left) and Maximilian Golla from the Max Planck Institute for Security and Privacy in Bochum collaborated for the study. Credit RUB, Marquard Usage Restrictions The image may only be used for reporting about the Ruhr-Universität Bochum in the context of the press release "How secure are four and six-digit mobile phone PINs", published in March 2020. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.