Should You Enable Encrypted Client Hello (ECH) in Cloudflare?
Encrypted Client Hello (ECH)—formerly known as ESNI (Encrypted Server Name Indication)—is a privacy-focused feature that encrypts the Server Name Indication (SNI) in TLS handshakes, preventing eavesdroppers from seeing which websites users visit. Cloudflare supports ECH, but should you enable it? Let’s break it down.
What ECH Does & Why It Matters
Enhanced Privacy
Traditional SNI exposes the domain you’re visiting, even if the connection is HTTPS.
ECH encrypts this metadata, making it harder for ISPs, governments, or attackers to track browsing habits.
Compatibility & Performance
Works with modern browsers (Chrome, Firefox, Edge).
Minimal latency impact—Cloudflare’s global network optimizes handshake efficiency.
Security Benefits
Prevents SNI-based censorship (e.g., regions blocking specific sites).
Reduces risks of man-in-the-middle (MITM) attacks targeting unencrypted SNI.