Utilizing Binary Code to Improve Usability of Pressure-based Authentication

Abstract Due to its invisibility feature, pressure is useful to enhance the security of authentication, especially preventing the shoulder surfing attack. However, users are more familiar with digital passwords than pressure-based passwords. In order to improve the usability of pressure-based authentication, this paper instantiates a pressure-based password (i.e., a sequence of pressures) to a decimal number. In addition, our approach features personalized pressure detection. The personalization further enhances security since an attacker must have a pressure habit that is consistent with the user. We conducted a series of user studies to compare the traditional four-digit password with our pressure-based password. The empirical result indicates that a pressure-based password is more resistant to the shoulder surfing attack than a four-digit password. However, it takes more time to input a pressure-based password on the first-time usage. The slowdown is caused by a modality change from vision to pressure. A field study that lasted for 10 days revealed that the side effect of modality change can be overcome through regular usages.