Android 17 supports ECH and protects home network privacy

When connecting to the home Wi-Fi network, a smartphone currently opens not only a path to the internet but also a view of other devices in the household. Android 17 introduces Local Network Protection: apps will have to request permission in the future if they want to scan the local network or communicate with other devices on it. This turns invisible app access into a visible decision.

The second new feature comes earlier in the connection process. Encrypted Client Hello (ECH) encrypts the name of the server a device wants to reach. Although the rest of the data traffic may already be largely encrypted, the DNS request — the search for the appropriate IP address — remained exposed for a long time. According to Google, observers could use it to determine which website someone wanted to visit. ECH works with private DNS; if a website does not yet support the technology, a random ECH extension is intended to make connection requests look similar from the outside.

Certificates will also become easier to monitor. With Certificate Transparency, certificates for connections to apps and websites are intended to be recorded in a public registry. This should reduce the likelihood that forged certificates are used to intercept data traffic and that such an attack goes undetected. For developers, Google points to modern networking libraries, including OkHttp 5.5.0, as well as technical recommendations for HTTPS-RR queries.

On mobile networks, carriers can activate a feature through a zero-click solution: 2G can be disabled by default for their customers. SMS blasters can force nearby smartphones to leave LTE or 5G and fall back to the older 2G network before sending phishing messages. Users have been able to disable 2G manually since Android 12. In Germany, O2, Vodafone and Deutsche Telekom want to shut down their 2G networks in 2028.

What happens next? For users, this means less invisible information about the household and fewer exposed clues about the websites they visit. For app developers, direct network access will require an explanation; secure system selection should still allow tasks such as streaming to a television. ECH is also not yet available everywhere, and Google is working with service providers and developers to expand its adoption. The safeguards are therefore built into Android 17, but their effectiveness also depends on apps, websites and mobile carriers.