Date Added: Jun 2011
As the Internet has entered everyday life and become tightly bound to telephony, both in the form of Voice over IP technology as well as Internet-enabled cellular devices, several attacks have emerged that target both landline and mobile devices. The authors present a variation of an existing attack, that exploits smartphone devices to launch a DoS attack against a telephone device by issuing a large amount of missed calls. In that light, they conduct an excessive study of Phone CAPTCHA usage for preventing attacks that render telephone devices unusable, and provide information on the design and implementation of the system that protects landline devices. Subsequently, they propose the integration of Phone CAPTCHAs in smartphone software as a countermeasure against a series of attacks that target such devices.