Media type: E-Article Title: Trust and Trustworthy Computing: Sensor Captchas: On the Usability of Instrumenting Hardware Sensors to Prove Liveliness Contributor: Hupperich, Thomas; Krombholz, Katharina; Holz, Thorsten imprint: Springer International Publishing, 2016 Published in: Trust and Trustworthy Computing Language: Not determined DOI: 10.1007/978-3-319-45572-3_3 ISSN: 0302-9743; 1611-3349 Origination: Footnote: