Android 17 Adds New Network Security Features to Block 2G SMS Blaster Attacks

Android 17 introduces platform-level network security controls to mitigate cellular downgrade (2G) attacks and reduce metadata exposure: carriers can opt to disable 2G by default to block SMS blaster operations, the OS adds Encrypted Client Hello (ECH) support to protect hostname privacy, enforces Local Network Protection to restrict app device discovery on Wi‑Fi, and enables Certificate Transparency by default to detect misissued TLS certificates. These defaults shift prior optional protections to system-level defenses against fraud, network reconnaissance, traffic interception, and profiling.