Signing email with an NFC smart card on Android
Last time we discussed how to access the SIM card and use it as a secure element to enhance Android applications. One of the main problems with this approach is that since SIM cards are controlled by the MNO any applets running on a commercial SIM have to be approved by them. Needless to say, that considerably limits flexibility. Fortunately, NFC-enabled Android devices can communicate with practically any external contactless smart card, and you can install anything on those. Let's explore how an NFC smart card can be used to sign email on Android. NFC smart cards As discussed in previous posts , a smart card is a secure execution environment on a single chip, typically packaged in a credit-card sized plastic package or the smaller 2FF/3FF/4FF form factors when used as a SIM card. Traditionally, smart cards connect with a card reader using a number of gold-plated contact pads. The pads are used to both provide power to the card and establish serial communication with its I/O...