Is it safe to use public networks?

What is a public network?

A public network is a WiFI network that is used publicly. Examples include networks in pubs and coffee shops, on public transport, in large buildings and at sporting events. You will be sharing access to this network with lots of other people and may find your access restricted if too many people are using the network at the same time.

Why is using a public network riskier than using my network at home?

Assuming you are not telling everybody your home WiFi password, you and your family/housemates SHOULD be the only people you are sharing your network with. However if you are on a train, in a pub or coffee shop or in a public building you will be sharing the network with strangers. If somebody who is sharing a network with you wishes you harm, this is one large hurdle that they no longer have to navigate. Think of it like living in a block of flats, you have a key to your own door and a key to the external door. Unless you trust everybody in the block of flats, you would be extra careful to leave your own door locked. For this reason you should be more careful on a public network.

If the website I'm visiting is https, surely it is safe to use on a public network?

Safer, much safer. https websites are substantially safer than the old http websites. But look at it this way. There is a constant arms race between cybercriminals and cybersecurity, with computers constantly being able to to more things faster. Something that is considered safe today could be considered laughably insecure in 5 years time. I do not wish to convey the idea that https sites are not safe in January 2022, I'd rather encourage best practices now because you never know what could get hacked in the future as criminals and technology become more advanced.

What are the risks involved using a shared computer?

You may find yourself using a shared computer in a library, at work or in a hotel. Everybody should have their own login (if not alarm bells should be ringing). Nonetheless your privacy is not great. System administrators would be able to access your files on the shared computer even if ordinary users couldn't. Thus it would be possible for others to see your browsing history on the shared computer. Another danger is that not everybody who used the computer is necessarily as safe as you. If they have downloaded any malware, it could affect everybody's accounts on the computer, not just their own. A shared computer is only as safe as its least safe user. Note that many companies and organizations will have installed their own firewalls and anti-virus protection. But better to be safe than sorry.