Thought Leadership
Google is introducing several new network security features with Android 17 that improve the protection of connection privacy.
In the future, Android 17 will support the Encrypted Client Hello standard, or ECH for short, which together with private DNS is intended to prevent third parties from profiling individual users based on visited domain names. ECH functions as a privacy extension for TLS—the protocol used to secure HTTPS connections—by encrypting the initial part of the TLS handshake, which normally reveals the contacted hostname via the so-called Server Name Indication. Even with a fundamentally secured connection, internet service providers and Wi-Fi operators can currently still see which specific destination a user is navigating to, which can be used commercially for profiling.
While Android users have benefited from ECH support at the browser level since Chrome 117 and Firefox 119, respectively, Android 17 now anchors the protection directly at the operating system level. In its own announcement, Google explains:
“This new privacy standard works alongside Private DNS to obscure the domain names you visit.”
By encrypting the destination site name from the start, network operators and eavesdroppers on the network should no longer easily be able to tell which sites or apps a user is actually visiting on supported websites and apps.
ECH will be enabled by default in the future for apps designed for Android 17, provided they use a compatible network library such as recent versions of OkHttp, WebView, or HttpEngine. If the respective server does not support ECH, Android instead sends a deceptively real-looking dummy field referred to as ECH GREASE, so that real ECH connections do not stand out in general traffic, although the hostname remains visible in this case. Google’s own privacy and censorship circumvention unit, Jigsaw, reportedly tested this mechanism against the 10,000 most visited domains and over 740 internet service providers in 202 countries without encountering loading issues or unexpected network blocks.
Android 17: Additional protection for home networks and end for insecure 2G
Additionally, Google announced further network protection features. The existing local network protection will in the future require explicit permission from apps before they can search for or connect to devices on a user’s local network. In addition, Android 17 enables so-called Certificate Transparency by default, meaning website certificates must appear in public logs in the future, making fake certificates easier to detect. Participating mobile carriers will also reportedly be able to automatically disable the older 2G standard for individual customers in the future, reducing the attack surface against so-called SMS blasters and rogue cell towers used to spread malicious messages or intercept sensitive data from nearby devices.
(Editorial Team)
