SSL vs TLS

SSL vs TLS: what actually changed between them

SSL and TLS do the same job — encrypt the link between a browser and a server — but SSL is retired and TLS 1.3 is what runs on almost every HTTPS site today. A certificate sold as "SSL" is a TLS certificate: the server picks the protocol version, not the certificate.

• SSL means Secure Sockets Layer: versions 2.0 (1995) and 3.0 (1996). Both are retired, and current browsers refuse them.
• TLS means Transport Layer Security: versions 1.0 (1999) through 1.3 (2018). Only 1.2 and 1.3 are still accepted in 2026.
• The handshake, the key exchange and the cipher suites changed between the two families. The purpose did not: privacy, integrity, and proof the server is the host it claims to be.

TLS is, in effect, SSL version 4. The protocol was renamed when Netscape handed it to the IETF in 1999, and every later fix shipped under the TLS name, so the old label stuck to the certificates rather than to the protocol.

From SSL 2.0 to TLS 1.3: the version timeline

Six protocol versions shipped between 1995 and 2018, and five of them are now switched off. A server that offers only TLS 1.2 and TLS 1.3 is not missing anything a visitor needs.

• SSL 2.0 (1995) and SSL 3.0 (1996): disabled in browsers after 2014; SSL 3.0 was formally retired in RFC 7568.
• TLS 1.0 (1999, RFC 2246) and TLS 1.1 (2006, RFC 4346): deprecated in RFC 8996 in March 2021 and rejected by current browsers and most payment gateways.
• TLS 1.2 (2008, RFC 5246): the floor. Card networks and Indian payment aggregators still require it during a security review.
• TLS 1.3 (2018, RFC 8446): the target. Chrome, Firefox, Safari, Edge, Android and iOS all ship it.

POODLE in October 2014 is why SSL 3.0 died so fast. The attack let an attacker recover plaintext by forcing a connection to fall back to the older protocol, and the practical fix was to stop speaking SSL at all.

How the TLS 1.3 handshake differs from the SSL handshake

TLS 1.3 completes the handshake in one round trip because the browser guesses the key agreement in its very first message. SSL and TLS 1.2 needed two: one exchange to agree on algorithms, a second to prove identity and confirm keys.

1. The browser sends a ClientHello listing the TLS versions it supports, a key share for a guessed (EC)DHE group, and its AEAD cipher suites.
2. The server replies with a ServerHello and its own key share. Both sides can now derive the handshake keys.
3. Everything after that is encrypted: the certificate, the CertificateVerify signature, and the server Finished message.
4. The browser validates the chain and the signature, returns its Finished, and sends the first HTTP request in the same flight.

A returning visitor can skip the key exchange entirely with a pre-shared key; that is the 0-RTT resumption path. SSL had no equivalent, and it also sent the certificate in clear text on every single connection.

Why the industry still says SSL certificate

Because buyers search for SSL and certificate authorities still print it on the product page. The certificate itself is protocol-neutral: a file that binds a domain name to a public key and is signed by a certificate authority.

What you actually choose when you buy is validation level and coverage — domain-validated, organisation-validated, extended-validation, single-name, wildcard or multi-domain. None of those settings change the protocol. The server configuration decides whether the connection runs over TLS 1.2 or 1.3.

So "SSL versus TLS certificate" is a false comparison. There is one certificate market and one live protocol family. The older name survives because renaming a product that buyers already search for costs sales, and because "SSL/TLS" is a convenient shorthand for the whole stack. For the certificate itself, read what an SSL certificate is.

TLS 1.3 speed and security gains over SSL

TLS 1.3 removes the delay and the weak options in the same edit, which is why it is both faster and harder to misconfigure than SSL or TLS 1.2.

• One fewer round trip before the first byte of HTML, which matters most on high-latency mobile links.
• Forward secrecy is compulsory: the session key comes from an ephemeral (EC)DHE exchange, so a stolen server key cannot decrypt traffic that was already recorded.
• AEAD ciphers only. RC4, 3DES, CBC-mode suites, MD5, SHA-1 and static RSA key transport are gone from the specification.
• The certificate is encrypted in transit, so a passive observer cannot read the hostname from the handshake.
• Five cipher suites instead of dozens, so there is far less room for a bad server default.

None of that helps if the account still answers on TLS 1.0. Check which version is negotiated before you tune anything else.

Which TLS versions your server should run in 2026

Enable TLS 1.2 and TLS 1.3, and switch off SSL 3.0, TLS 1.0 and TLS 1.1. Keep 1.2 as a fallback because older Android devices, some point-of-sale terminals and a few payment APIs in India still cap there. TLS 1.3 alone will lock out real customers.

On a shared plan, do not paste SSLProtocol into .htaccess. Apache rejects the directive in that context and returns an internal server error instead of a stronger connection.

How to test which TLS version your site uses

Two terminal commands settle it, and both run on Linux, macOS or WSL. Swap in your own domain.

1. Run openssl s_client -connect example.com:443 -tls1_3 </dev/null and look for a line reading Protocol : TLSv1.3. A handshake failure means 1.3 is off.
2. Run the same command with -tls1_1. If it connects, a retired protocol is still open on the server.
3. Open the site in Chrome, click the padlock, then Connection is secure. The panel names the protocol and cipher the browser negotiated.
4. For the full cipher list, run the domain through the WebJi® SSL checker or any SSL Labs-style scanner and read the Protocol Support row.

You know it worked when the 1.3 command prints Protocol : TLSv1.3 and the 1.1 command fails. If 1.1 still connects after a control panel change, the setting was saved to the wrong vhost or the web server never reloaded.

What a certificate does, and what it cannot do

A certificate proves that the domain is controlled by the account presenting it, and hands the browser a public key to encrypt against. It does not choose the protocol, the cipher, or the HSTS policy. Those are server settings.

That is why "upgrade your SSL certificate to TLS" is not a product you can buy. You replace a certificate when it expires, when the covered names change, or when you need organisation validation. The protocol upgrade is free and lives in the web server configuration.

WebJi® issues certificates through its SSL certificate service: Sectigo Positive SSL at ₹1,800 per year for one domain with www, and Sectigo Positive SSL Wildcard at ₹7,500 per year for a domain and all its sub-domains, both before 18% GST. Let's Encrypt certificates are included free with hosting plans. If you are still choosing between the two families, free versus paid SSL covers the warranty and validation difference.