TLS vs SSL: Encryption Protocol Evolution

Mon, 03 Aug 2026 04:17:43 +0900

Overview

SSL and TLS are cryptographic protocols that secure data in transit between clients and servers, but SSL is the deprecated predecessor while TLS is its actively maintained successor. Every SSL version is now broken or prohibited, yet the term “SSL” persists in everyday usage even though modern connections actually negotiate TLS.

Comparison Diagram

Comparison Table

Aspect	SSL	TLS
Origin	Developed by Netscape starting in 1995	Standardized by the IETF in 1999 as SSL’s successor
Versions released	SSL 2.0, SSL 3.0 (SSL 1.0 never shipped)	TLS 1.0, 1.1, 1.2, 1.3
Handshake process	Full handshake only, with weaker key exchange options	Streamlined handshake; TLS 1.3 cuts a round trip and defaults to forward secrecy
Cipher suite support	Permits weak ciphers like RC4, DES, and export-grade crypto	Mandates modern AEAD ciphers (AES-GCM, ChaCha20-Poly1305); weak ciphers dropped entirely in 1.3
Known vulnerabilities	POODLE broke SSL 3.0; DROWN broke SSL 2.0	BEAST and CRIME hit early TLS 1.0 but were patched in later versions
Current status	All versions formally deprecated and prohibited (RFC 7568)	TLS 1.2 and 1.3 are the current standards; 1.0/1.1 also deprecated
Everyday terminology	“SSL certificate” and “SSL/TLS” persist as colloquial shorthand	The protocol actually negotiated by nearly every modern HTTPS connection

Key Differences

SSL is the obsolete predecessor; TLS is the actively maintained successor protocol
TLS 1.3’s handshake trims a round trip compared to SSL’s full handshake
SSL still permits weak ciphers like RC4; TLS mandates modern AEAD ciphers
The label “SSL certificate” survives in marketing even though browsers negotiate TLS
SSL 3.0 was broken by POODLE, forcing its complete deprecation

When to Use Each

SSL

HTTP vs HTTPS: Plaintext vs Encrypted Web Traffic

Sat, 01 Aug 2026 20:01:00 +0900

Overview

HTTP and HTTPS are the same application-layer protocol for transferring web resources, but HTTPS wraps every request and response in a TLS tunnel before it touches the network. That single layer determines whether credentials, cookies, and page content travel as plaintext visible to anyone on the path, or as ciphertext only the two endpoints can read.

Comparison Diagram

Comparison Table

Aspect	HTTP	HTTPS
Default port	80	443
Connection establishment	Single TCP three-way handshake	TCP handshake plus a TLS handshake to negotiate cipher and exchange keys
Certificate requirement	None	X.509 certificate issued by a trusted CA (or self-signed) required
Data encryption	Plaintext — headers, cookies, and body sent unencrypted	Encrypted end-to-end using TLS/SSL symmetric ciphers
Data integrity	No built-in tamper detection	MAC/AEAD in TLS detects in-transit tampering
Browser indicator	“Not secure” warning in modern browsers	Padlock icon; no warning shown
Performance overhead	Lower — no crypto or extra round trip	Slightly higher handshake/CPU cost, largely offset by TLS 1.3 and session resumption
Typical use case	Local development, internal tools on trusted networks, legacy static content	Any production site, especially logins, payments, and APIs handling sensitive data

Key Differences

HTTPS is HTTP tunneled through TLS, not a separate application protocol
HTTP traffic is readable in plaintext by anyone with network access; HTTPS traffic is encrypted
HTTPS requires a valid certificate from a trusted CA to establish trust
Modern browsers flag HTTP sites as not secure, pushing HTTPS as the default
TLS 1.3 has shrunk the historical HTTPS handshake cost to near parity with plain TCP

When to Use Each

HTTP

Tls on IT Comparison

TLS vs SSL: Encryption Protocol Evolution

Overview

Comparison Diagram

Comparison Table

Key Differences

When to Use Each

HTTP vs HTTPS: Plaintext vs Encrypted Web Traffic

Overview

Comparison Diagram

Comparison Table

Key Differences

When to Use Each