Pay-Cloak: A Biometric Back Cover for Smartphones: Facilitating secure contactless payments and identity virtualization at low cost to end users. - Alak Majumder; Joyeeta Goswami; Shirsha Ghosh; Rishu Shrivastawa; Saraju P. Mohanty; Bidyut K. Bhattacharyya (IEEE Consumer Electron. Mag., 2017)