How can I safely use public networks or shared computers?

Updated:July 2016

Sometimes it’s necessary to use public internet or shared computers during an assignment. Using these can be considerably less safe than using your own.

To be clear, there are no secure open networks or public computers. Working on a sensitive issue in a public place is sometimes necessary. However, this can involve increased security risks, ranging from others seeing what's on your screen to people using software to try to hack into your computer. The internet service provider may also be keeping logs about what you do. What follows are some methods and software that can help you reduce the risks.



Using your own computer on a shared network

Address the physical surroundings:

Look around before getting down to work. Check out the physical location. Who's around you and what's going on? When using a computer in a public area like a cyber café, be aware of the surroundings. Try sitting in a location where there isn't someone physically behind you. If possible, sit somewhere that offers a wall directly to your back. Make sure you're not being visibly observed making a sensitive connection and that the content on your screen isn't readily visible to people who may be nearby. This isn't  the place to have potentially confidential internet voice or video chats. Even if you're using headphones, others will still hear your half of them.

Securing your computer:

You're in a public place, and a physical attack can be as likely as a digital one. Beware of snatch-and-grab attempts. A person can run off with your computer in seconds. Consider where you are in a place, who's around you and what's between you and the exit. Never leave your computer unattended for any length of time. Don't rely on a stranger to "keep an eye on it."  It should be password protected, and having an encryption-protected hard drive is highly recommended. If you use your computer in public settings frequently, you may want to invest in a security cable.

Related resource: How can I keep my content safe if my computer is taken?

Be careful how you're connecting and what you're connecting to:

Public internet access areas usually have weak or non-existent security measures in place. This makes them prime targets for hackers. Malware attacks and social engineering attempts are common on public networks. The most important thing to remember is that there will be others sharing the same network or WiFi hotspot, and you don't know anything about them.

Things to have ready before you've connected:

1) Make sure you're computer's operating system and the web browser and other software are up to date.

2) Install and use anti-virus software to alert you about potentially dangerous downloads and block suspicious web traffic.

3) Do not use Internet Explorer. Actually, uninstall it now. Latest versions of Chrome and Firefox have a number of security settings you should familiarize yourself with. Block cookies, pop-up windows and JavaScript during sessions on public networks. There are a number of extensions or add-ons available for either Chrome or Firefox that can add additional protection.

4) Use 2-factor authentication in your accounts. This will help keep others out of your accounts. If you're on a comprimised wireless connection, then even if an attacker is able to collect your login details they still won't be able to access your account without this second one-time password. Many services that use 2-factor authentication will keep a record anytime a new attempt to log in is made, alerting you if someone is trying to break in.

5) Add some useful browser plugins. The HTTPS Everywhere extension to your browser to help ensure that when a website has an encrypted connection available, you're using it.  AdBlock Plus is a plugin for Firefox or Chrome that blocks ads, but also can stop other kinds of code that could be dangerous. While NoScript Security Suite can sometimes make websites not work quite right, it does block a number of programs from violating your privacy.

6) For enhanced privacy, have a VPN account or a proxy service, such as Tor, ready to use. Encrypt your activity before it leaves your computer and add strong protection to the information that you're accessing online. If the connection is being monitored or records are being saved, then this will disguise your activity.

Things to do when you're connecting:

Make sure you're connecting to the correct network. Find out what the exact network name is before joning. Be wary of slight differences in the name you find in your network options. There could be a fake connection trying to lure you away from the authentic network. (Poorly secure authentic networks can also be hacked, though, so still take precautions on any public network).

2) Choose the most secure connection option possible. When joining the network, you should need to enter a password. It should allow you to use a"WPA" or "WPA2" password. If it is using a "WEP" password, then the connection isn't secure.

3) Be watchful for suspicious things happening on your screen. Do you suddenly get pop-up ads or invitations? Does an email arrive from someone you don't recognie with links or downloads? Is your web browser  diverted to a page you didn't intend or to a form asking for personal information? Be targeted in your work when using a public network to access the internet. Don't click on anything you didn't already plan to do and if something starts looking strange, shut down or disconnect.

4) Make sure your computer's other network settings are closed off. Don't allow file sharing of any sort. Turn off Bluetooth to keep your device from being discoverable by mobiles or PCs with it active.

5) Make sure the site's URL includes "https" at the start and never enter any personal details in a site without this, otherwise you're transmitting information using plaintext and it can be easily read by others. Sites with an SSL connection also allow you to check whether you're on the right one and not be diverted to a fake. You can learn how to do this manually, or use a tool to check a certificate, such as the one at Symantec.

Be prepared:

Using a cyber cafe's computer

Using a cyber cafe's computer for work is highly risky behaviour and should be seen as an activity of last resort! Keep your activity as limited as possible and be aware that there is virtually no way for you to check that your connection is confidential. For casual web browsing, it can be useful, so long as you remember that the activity can be logged and retrieved by the cyber cafe employees or those who ask them for their records, and possibly others using the same computer after you.

Adopt these habits and methods:

If you find yourself needing to use a public computer, here are some basic things to remember:

  • Pay for your session in cash, and try not to use services that require your personal information.
  • Don’t save any files to the hard drive. (Have a USB stick ready)
  • If you do need to log into anything, always make sure not to let the computer remember any login details. Usually the computer and/or browser will ask you if you want to remember the login details. Click "no."
  • Don't use Internet Explorer. If installed, use private browsing options on Chrome, Safari or Firefox. This tells the browser to not remember information about your activity. If, for some reason, you do use IE, use the"InPrivate Browsing" option. When using private browsing, it's good to remember that it is only preventing the browser from storing information about what you're doing on the computer. Your activity could still be logged by other software, or by the networks you access, and with the cyber cafe as well.
  • Before ending a web browser session, make sure to empty the history, cookies, cache and anything else.
  • Many cyber cafe public computers come installed with other kinds of software, such as Skype. Don't use them. Whenever you log into Skype (for example), the local computer will create a copy of all your settings, logs, contacts and text messages. Anyone knowing where these are stored will be able to find them, even if they don't log in as you. Limit your activity to the web browser and make sure you maintain an absolutely minimal digital footprint.
  • Having 2-step authentication is even more important when using a personal account on a shared computer. The account won't recognize the new computer and will send your mobile a temporary password to use for that session. When you log in, the account will ask if you want to keep this computer in your list of approved locations. Click "no." This will block others from using it later and alert you if anyone tries.
  • As soon as you're back on a device that is your own, and on a private network, update any passwords you used on the public computer.
Use a USB stick, disc or a portable device:

This isn't always possible. Some internet cafe computers allow it, and others may not. That said, there are different ways to use USB sticks, DVD discs or other portable devices that can be plugged into a computer.

1) At a minimum, have a spare USB stick to store any files you need, and only work from that USB stick. Don't need to rely on any of the computer's folders.
How can I safely use public networks or shared computers?

Be aware of your surroundings both in the physical space and the network you're using to connect to the internet.
2) Tails is an entire computer operating system and software package that can fit on a USB stick or DVD disc. Everything is designed to provide out-of-the-box internet security on any desktop or laptop computer. Turn off the computer, plug in the Tails drive and restart it. You'll need to practice with it before trying it out in the field, but it will keep any activity from being stored on the computer you're using.
3) You may not need a whole computer operating system on a portable memory stick, or have the time to learn how it works. For many people, a simple, secure web browser will do just fine. The Tor Browser Bundle can run on a USB stick, and is easy to set up. Remember when using Tor, that there are some simple practices to keep in mind. This page has them listed.

4) GPG4USB is software that allows you to receive and send encrypted communication from anywhere. Locally encrypting and decrypting content on a USB stick makes it easier to remain unreadable when it's loaded into the computer's system.


Image credit: Delayed Gratification.

Created: July 2013

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