Travel: why avoid public Wi-Fi to protect your personal data

Public Wi-Fi networks are practical to connect to the Internet for free, especially on the go. But their use can expose your personal data to significant security risks.

The danger of public Wi-Fi networks

Public Wi-Fi is a wireless internet network available free of charge in places open to the public. It allows you to connect to the Internet without using your mobile package. It is found everywhere: in cafes and bars, but also in stations and airports, and you may use it if you travel a lot. But beware, because it does not require a secure password, which makes it more vulnerable to the risk of hacking or interception of personal data. In 2024, in Paris for example, researchers Kaspersky noted that 25% of them are not sure.

A pirate connected to the same network that you can intercept what you send or receive, such as your passwords, your messages, or the contact details of your bank card. This is called a “Man-in-The-Middle” type attack, where the pirate is discreetly inserted between you and the website you consult.

Worse, some hackers create false Wi-Fi networks with misleading names, such as “Café_Gratuit“ or “Hotel_wifi_free”, to encourage passers-by to connect to it. Once connected to this trapped network, your device can be fully exposed.
“” “You have to be very careful with these public Wi-Fi networks. Some are provided by cafes. Others try to pretend to be coffee”Said Christine JulienIT teacher at Virginia Tech.

Fortunately, there are techniques to protect yourself and avoid these attacks. First of all, never accept sensitive services (such as your bank or administrative accounts) from a public network. Also avoid connecting to the known networks automatically: a false network can very well resume a name that your phone recognizes. If you really have to use public Wi-Fi, use a VPN : it figures your data and prevents any interception. And for more security, deactivate Wi-Fi when you do not use it, and favor mobile connection sharing or a 4G/5G connection for sensitive operations.

Finally, unfortunately, this is not the only subject for which Christine Julien is concerned. The scientist also warns against USB charging stations. These charging stations can be used for a technique called “juice jacking”. The USB port is not only used to recharge: it can also transfer data. A pirate can therefore infect a public terminal with malware that spreads to your phone as soon as it is connected. “”I advise you to pay attention to the contextual windows that could appear on your phone“, advises Julien. This time, prefect the use ofexternal batteries.