Android 17 Adds Encrypted Client Hello to Hide Which Sites You Visit From Network Snoops

Android 17 adds support for Encrypted Client Hello, a privacy standard that hides which websites and apps a phone is connecting to from internet providers, Wi-Fi operators and anyone else watching the network. Google announced ECH as one of four new network security features in the release and called Android 17 “the first major mobile OS to enable broad ECH support.”

Closing the last visible gap in HTTPS

Even with HTTPS, the domain name of the site you visit is still visible to network operators and eavesdroppers. “This unencrypted data can be used to build user profiles or, in the hands of malicious actors, leveraged for targeted phishing and scam campaigns,” Google wrote.

ECH encrypts the destination name from the start of the connection and works alongside private DNS, which encrypts the lookup itself. For supported websites and apps, network providers can no longer easily see where a device is going. Google says it is working with its Jigsaw unit, service providers and app developers to speed up adoption, and it’s asking Android developers to upgrade to OkHttp 5.5.0 and enable ECH. Coverage will depend on how many sites and apps support the standard.

Three more protections

• Local Network Protection: Apps now need permission before they can scan or connect to other devices on your home network, closing a way to profile households by their smart TVs, cameras and consoles. For tasks like casting, Google wants developers to use a system picker so the app never sees the rest of the network.
• Certificate Transparency by default: Certificates must be logged in a public registry, making it much harder for an attacker with a fake certificate from a compromised issuer to intercept traffic unnoticed.
• Carrier-controlled 2G shutoff: Android 12 added a manual switch to disable 2G. Android 17 lets participating carriers turn 2G off by default, cutting off the downgrade trick that “SMS blaster” fake base stations use to push scam texts past modern filters. Google notes that this hardware now costs as little as $3,000.

For enterprises managing Android fleets, the changes are mostly upside: less metadata leaking on untrusted networks, fewer apps mapping corporate or home networks, and stronger defenses against certificate abuse. App teams should test anything that discovers local devices, since those flows now need the new permission or the system picker.