SSL vs TLS: What Is the Difference?
SSL and TLS are both protocols for encrypting internet connections, but they are not the same. This guide explains the history, the differences, and why only TLS should be used today.
ProfitTool Team
Security & Dev
A Brief History
| Version | Year | Status |
|---|---|---|
| SSL 1.0 | 1994 | Never released (serious flaws) |
| SSL 2.0 | 1995 | Deprecated 2011, RFC 6176 |
| SSL 3.0 | 1996 | Deprecated 2015, RFC 7568 (POODLE attack) |
| TLS 1.0 | 1999 | Deprecated 2021, RFC 8996 |
| TLS 1.1 | 2006 | Deprecated 2021, RFC 8996 |
| TLS 1.2 | 2008 | Supported — widely used |
| TLS 1.3 | 2018 | Recommended — fastest, most secure |
Why SSL Is Broken
SSL 3.0 was vulnerable to the POODLE attack (Padding Oracle On Downgraded Legacy Encryption), which allowed attackers to decrypt encrypted data by exploiting the protocol's padding scheme. TLS 1.0 and 1.1 had similar issues including BEAST and POODLE-TLS.
TLS 1.2 vs TLS 1.3
TLS 1.3 made significant improvements:
- Faster handshake: 1-RTT (vs 2-RTT in TLS 1.2), with 0-RTT resumption option
- Forward secrecy only: removed cipher suites without PFS
- Removed weak algorithms: RC4, SHA-1, MD5, DES, 3DES removed entirely
- Encrypted handshake: more of the handshake is encrypted, reducing fingerprinting
What "SSL Certificate" Actually Means Today
The term is a holdover. Modern certificates are X.509 certificates used by TLS, not SSL. Every major CA issues certificates that work with TLS 1.2 and 1.3. The certificate format did not change — only the protocol negotiating how to use it.
Checking TLS Version Support
When you check an SSL certificate, modern checkers will also show which TLS versions the server supports. A server still accepting TLS 1.0 or 1.1 should be reconfigured.
Use our SSL Certificate Checker to inspect any domain's certificate chain and verify its validity.
ProfitTool Team
Security & DevWritten and maintained by the ProfitTool team. Where an article references a ProfitTool utility, the behaviour described is the behaviour of the tool on this site — you can open it and check the output yourself.
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