Proximity technologies work in a radius of inches or centimeters. These include technologies such as Near Field Communication (NFC), Bluetooth, and Radio Frequency Identification (RFID). Most of these technologies have been around for some time but the pervasiveness of mobile devices has given them an array of new use cases. These technologies are now being used for mobile payments, pairing of different devices, identification, and authentication.
Bluetooth is now a standard in most mobile phones. It is a wonderful technology to pair devices. With devices such as glasses and watches coming in the market, this might be the technology that brings them all together.
Both NFC and RFID work by producing an electromagnetic field that modulates at a certain frequency. Since these tags are world readable, when used as tags or identification mechanism, these tags pose privacy risk. The first NFC enabled Android phone, the Nexus S, came out in the year 2010. The Android SDK comes...