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09. 08. 2026 When browsing the web, you often notice a padlock icon next to the URL and the prefix https:// instead of unencrypted http://. This indicates that the website is secured with an SSL/TLS certificate. In this article, we will explore how SSL works, how it encrypts data transfer, and why it is critical for online store security and search engine ranking.
Difference Between HTTP and HTTPS
The primary difference between the protocols lies in the security of data transmitted between the user browser and the web server.
| Feature | HTTP Protocol | HTTPS Protocol (with SSL/TLS) |
|---|---|---|
| Data Security | Data travels in plain unencrypted text. | Data is strongly encrypted prior to transit. |
| Credential Protection | Intermediaries can read intercepted packets. | Interceptors only see encrypted unreadable noise. |
| SEO & Trust | Flagged as "Not Secure" by modern browsers. | Displays a green padlock icon and gains SEO advantages. |
How the SSL Handshake Works
When visiting a secure website, an asymmetric and symmetric encryption handshake takes place automatically within milliseconds.
- Client Hello: The browser connects to the server requesting a secure session.
- Certificate Delivery: The server sends its SSL certificate containing the public key.
- Authentication Verification: The browser verifies the certificate validity against a trusted Certificate Authority (CA).
- Session Key Exchange: A unique symmetric session key is generated to encrypt all subsequent traffic.
Types of SSL Certificates
Depending on the validation depth, several certificate tiers exist. Most websites and personal blogs use free DV (Domain Validation) certificates (e.g., Let's Encrypt). Corporations and financial institutions typically utilize OV (Organization Validation) or EV (Extended Validation) certificates, which require rigorous legal entity checks.
Why Every Website Needs SSL
Beyond safeguarding user credentials and payment card details, SSL certificates are an essential search engine ranking factor for Google. Websites lacking SSL lose visitor trust and search visibility.