DIGITALSECURITYGUIDE look as though they are switched off. • Never allow people you don't trust get physical access to your phone; this is a common way of installing spying software on your phone. • If you are conducting private and important meetings, switch your phone off and disconnect the battery. Or don't carry the phone with you if you can leave it where it will be absolutely safe. • Make sure that any person with whom you communicate also employs the safeguards described here. • In addition, don't forget that using a phone in public, or in places that you don't trust, makes you vulnerable to traditional eavesdropping techniques, or to having your phone stolen. About interception of calls Typically, encryption of voice communications (and of text messages) that travel through the mobile phone network is relatively weak. There are inexpensive techniques which third parties can use to intercept your written communications, or to listen to your calls, if they are in proximity to the phone and can receive transmissions from it. And of course, mobile phone providers have access to all your voice and text communications. It is currently expensive and/or somewhat technically cumbersome to encrypt phone calls so that even the mobile phone provider can't eavesdrop – however, these tools are expected to become cheaper soon. To deploy the encryption you would first have to install an encryption application on your phone, as well as on the device of the person with whom you plan to communicate. Then you would use this application to send and receive encrypted calls and/or messages. Encryption software is currently only supported on a few models of so-called 'smart' phones. Conversations between Skype and mobile phones are not encrypted either, since at some point, the signal will move to the mobile network, where encryption is NOT in place. Security settings for android smartphone 1.1 ACCESS TO YOUR PHONE Enable Lock SIM card, found under Settings -> Personal -> Security -> Set up SIM card lock. This will mean that you must enter a PIN number in order to unlock your SIM card each time your phone is switched on, without the PIN no phone calls can be made. Set up a Screen Lock, found under Settings -> Personal -> Security -> Screen Lock, which will ensure that a code, pattern or password needs to be entered in order to unlock the screen once it has been locked. We recommended using the PIN or Password option, as these are not restricted by length. You can find more information on creating strong passwords in How to create and maintain secure passwords. Set the security lock timer, which will automatically lock your phone after a specified time. You can specify a value which suits you, depending on how regularly you are willing to have to unlock your phone. 1.2 DEVICE ENCRYPTION If your device uses Android version 4.0 or newer, you should turn on device encryption. This can be done in Settings -> Personal -> Security -> Encryption. Before you can utilise device encryption, however, you will be required to set a screen lock password (described above). Note: Before starting the encryption process, ensure the phone is fully charged and plugged into a power source. 1.3 NETWORK SETTINGS Turn off Wi-Fi and Bluetooth by default. Ensure that Tethering and Portable Hotspots, under Wireless and Network Settings, are switched off when not in use. Settings -> Wireless & Networks -> More -> Tethering & Mobile 25