Upgrade TLS 1.2 to TLS 1.3

Problem

The server negotiates TLS 1.2. It is still considered secure, but it is an older protocol: the handshake needs two round trips, supports weaker legacy cipher suites (CBC, RSA key exchange) and lacks modern privacy features.

Why it matters

• Speed: TLS 1.3 completes the handshake in one round trip (and zero with 0-RTT resumption), cutting connection latency — especially on mobile networks.
• Security: TLS 1.3 removes obsolete algorithms entirely (RSA key exchange, CBC modes, SHA-1), so misconfiguration is much harder.
• Forward secrecy is mandatory in TLS 1.3, optional in 1.2.

How to fix

• nginx: ssl_protocols TLSv1.2 TLSv1.3; (keep 1.2 for old clients, prefer 1.3).
• Apache: SSLProtocol -all +TLSv1.2 +TLSv1.3.
• CDN/proxy (Cloudflare, Fastly, ALB): enable TLS 1.3 in the TLS settings panel — usually one switch.
• Verify: openssl s_client -connect host:443 -tls1_3.

Related: Legacy TLS versions