What is SSL/TLS and Why Do Websites Need It?

Ahmet Aykut Birlik

What is SSL/TLS and Why Do Websites Need It?

When you type a web address into your browser, you may notice that some sites start with http:// and others with https://. The extra “s” stands for secure, and that security is provided by SSL/TLS certificates.

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are the technologies that make modern web browsing safe. They encrypt the data traveling between your browser and a web server, preventing attackers from eavesdropping, stealing information, or modifying traffic.

In this article, we will explain what SSL/TLS is, how it works, and why every website should use it.

What is SSL/TLS?

SSL/TLS is a cryptographic protocol that provides:

Encryption → Protects sensitive data like passwords, payment details, or personal information.
Authentication → Confirms that the website you’re visiting really belongs to the organization it claims to.
Data Integrity → Ensures that information is not altered during transmission.

Although people often still say “SSL,” the industry-standard protocol today is TLS (versions 1.2 and 1.3). TLS is simply the modern, more secure evolution of SSL.

How Does SSL/TLS Work?

When you connect to a website using HTTPS, the following process happens in milliseconds:

Handshake → The browser and server agree on which version of TLS and which encryption algorithms to use.
Certificate Exchange → The server presents its SSL/TLS certificate, which is validated by the browser against trusted Certificate Authorities (CAs).
Key Exchange → A secure session key is generated using public/private key cryptography.
Encrypted Communication → All data exchanged is encrypted with that session key.

Example:

You → (Hello, I want to connect securely)
Server → (Here’s my certificate, signed by CA)
You → (I trust the CA, let’s generate a key)
Server ↔ You → (All further communication encrypted)

Why Do Websites Need SSL/TLS?

1. Security for Users

Without SSL, data like login credentials or payment details can be intercepted by attackers through “man-in-the-middle” attacks. With SSL/TLS, this data is encrypted and unreadable to outsiders.

2. Authentication and Trust

Certificates are issued by trusted Certificate Authorities (CAs). When users see the padlock symbol 🔒 in the browser, they know the site is verified and safe.

3. SEO Benefits

Google uses HTTPS as a ranking signal. Sites without SSL are penalized in search results, while HTTPS sites gain higher visibility.

4. Browser Warnings

Modern browsers like Chrome, Firefox, and Edge mark non-HTTPS sites as “Not Secure.” This scares users away and damages brand trust.

5. Compliance Requirements

Regulations like GDPR, PCI DSS, and HIPAA often require encryption for sensitive data. SSL/TLS is a baseline security measure for compliance.

Types of SSL Certificates

Not all SSL certificates are the same. They differ in validation level and use cases:

DV (Domain Validated) → Basic, verifies domain ownership only.
OV (Organization Validated) → Confirms both domain and business identity.
EV (Extended Validation) → Highest level of trust, often used by banks and large enterprises.

For most small-to-medium websites, DV or OV certificates are sufficient.

Free vs Paid SSL Certificates

Free (e.g., Let’s Encrypt) → Great for blogs, personal websites, or small projects. They are automated and renew every 90 days.
Paid → Offer extended validation, warranty, and enterprise-level support. Best for e-commerce, banking, and critical applications.

How to Get Started with SSL/TLS

Choose a Certificate Authority (Let’s Encrypt for free, DigiCert, Sectigo, or GlobalSign for paid).
Generate a CSR (Certificate Signing Request) on your server.
Install the Certificate on your web server (Nginx, Apache, IIS, etc.).
Redirect All HTTP to HTTPS to enforce secure browsing.
Enable Auto-Renewal for Let’s Encrypt or set reminders for paid SSL renewals.

Example Nginx config for HTTPS redirect:

server {
    listen 80;
    server_name example.com www.example.com;
    return 301 https://$host$request_uri;
}

Future of SSL/TLS

The industry is rapidly adopting TLS 1.3, which provides faster handshakes and stronger encryption. At the same time, older protocols like SSL 3.0 and TLS 1.0/1.1 have been deprecated due to security vulnerabilities.

Organizations should ensure that their servers and applications are configured to use modern protocols and strong ciphers.

Conclusion

SSL/TLS is no longer optional—it is a requirement for all websites. It protects users, builds trust, improves SEO, and ensures compliance with global standards.

Whether you are running a personal blog, a SaaS application, or an enterprise-grade platform, enabling HTTPS with SSL/TLS is the first step toward secure and modern web infrastructure.

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