Public Wi-Fi networks, found in cafes, airports, or hotels, offer convenient Internet access when mobile coverage is insufficient. However, these connections are not without risks. Between data collection and spying possibilities, it is essential to understand what these networks can see about your online activity and how to protect yourself effectively.
The 3 key points not to miss
- Public Wi-Fi networks can collect information about your device and browsing habits through identifiers such as the MAC address.
- Although encrypted content remains secure, metadata like domain names and IP addresses can still be observed.
- Using protective measures such as VPNs and disabling automatic connection to open networks can enhance security.
Information collected by public Wi-Fi networks
When you connect to a public Wi-Fi, your device automatically shares certain information. Among these, the MAC address, a unique identifier that, although anonymized by random addresses on many modern devices, can still be used to track your connections.
Additionally, other contextual data such as the device name or technical capabilities may be transmitted. For example, if your device is named “Claire’s iPhone,” this name could appear in the network administration tools, making your device more identifiable.
Data security and encryption
With the widespread use of HTTPS, the content of websites and applications is encrypted, preventing Wi-Fi networks from directly reading your messages or passwords. However, metadata, such as unencrypted DNS queries or TLS connection information, can still be visible.
Technologies like DNS over HTTPS (DoH) or Encrypted Client Hello (ECH) aim to protect this information, but their availability depends on the hardware and software used.
Risks associated with using public Wi-Fi networks
Public networks can be exploited to collect statistical data or for marketing actions, especially if a captive portal requests personal information to connect. Moreover, fake Wi-Fi networks, which mimic those of legitimate places, pose a major risk by attempting to trap users to steal their data.
In the face of these dangers, it is recommended to disable automatic connection to open networks and keep your devices updated to protect against attempts to exploit known security vulnerabilities.
Protecting your browsing with a VPN
Using a VPN is an effective way to protect your data on a public Wi-Fi network. By encrypting Internet traffic, a VPN reduces the amount of information the network can collect, including the domains visited.
However, even with a VPN, it is important to remain vigilant about the information you voluntarily enter, such as account logins or online forms. A VPN should be considered a complement to good security practices, rather than a substitute.
Context and history of public Wi-Fi
Public Wi-Fi networks emerged as an affordable and convenient solution for accessing the Internet in public places. At a time when mobile data plans were expensive and limited, connecting to free Wi-Fi was a popular alternative. However, with the evolution of mobile technology and the decrease in data costs, the use of public Wi-Fi has become more a matter of convenience than necessity.
Despite their practicality, these networks have always raised security concerns, prompting the adoption of encryption technologies and more advanced security measures to protect users. Today, with the rise of cyberattacks and data breaches, security on these networks remains a concern, prompting users to adopt secure practices such as using VPNs and disabling automatic connections.
