Android 17 Hides Visited Websites From Carriers and Blocks Local Network Scanning

Google has unveiled a major suite of network privacy enhancements coming to Android 17. The new mobile operating system release adds native support for Encrypted Client Hello (ECH), which hides visited domain names from ISPs, and restricts apps from accessing devices on local Wi-Fi networks.

ECH Encryption: Why Standard HTTPS Is No Longer Enough

Under a standard secure HTTPS connection, ISPs and public Wi-Fi providers cannot read transmitted traffic, login credentials, or passwords. However, during initial connection setup, the website’s domain name remained exposed: network observers could see that a smartphone was connecting to example.com, for instance, even if they didn’t know the specific page being viewed.

As reported on the Google Security Blog, Android 17 integrates Encrypted Client Hello (ECH), working alongside the Private DNS protocol. The technology fully encrypts request metadata starting at the initial TLS handshake:

• carriers and router administrators can no longer log or compile lists of websites visited by users;
• protection requires server-side and website support (software developers are advised to upgrade to network library OkHttp 5.5.0 or higher);
• Android 17 becomes the first major mobile OS with deep system-level integration of the standard.

Engineers clarify that ECH does not turn a smartphone into a VPN or Tor alternative: ISPs can still detect network activity, total megabytes transferred, and the destination server IP address.

Protecting Local Networks From Hidden Scanning

Another key security enhancement is the Local Network Protection feature. Previously, any installed app could quietly scan a home Wi-Fi network, create a digital fingerprint of connected devices (smart TVs, smart speakers, network-attached storage, security cameras), and use that data for covert tracking or finding IoT vulnerabilities.

According to the Android developer documentation, local network access is now blocked by default:

• apps must request a separate system permission from the user;
• for common tasks (like casting video to a TV), an isolated system picker has been added — streaming video to the selected screen without granting the app access to other home devices.

Blocking Fake Base Stations and Certificate Verification

Google has also strengthened defenses against so-called SMS blasters — portable fake cell towers that generate radio interference to force victims’ smartphones to downgrade from LTE/5G to the vulnerable 2G protocol. Attackers then use the unencrypted connection to send phishing messages, bypassing carrier spam filters.

While users previously had to disable 2G manually in settings, Android 17 gives telecom operators a tool to centrally disable the legacy standard for their subscribers by default.

Additionally, the OS now enforces mandatory checks via Certificate Transparency — all website TLS certificates are verified against global public logs, eliminating traffic interception via fraudulent or compromised certificate authorities.