SSL Certificate: What Is It, What Types Are There, and Why Do You Need It?

The Green Padlock, HTTPS and Data Security – Discover the Secrets of SSL Certificates!

Have you ever noticed the green padlock and the “https” prefix in your browser’s address bar when visiting certain websites? It’s not just decoration — it’s a visible sign that the site takes care of your security thanks to an SSL certificate. In today’s digital world, where data privacy and user trust are worth their weight in gold, SSL has become an absolute standard for every professional website. In this article, we’ll explain exactly what SSL is, what types exist (including popular paid and free options like Let’s Encrypt) and why your WordPress site (and beyond!) must have one.

What Is an SSL/TLS Certificate and How Does It Work? The Basics of Encryption

SSL (Secure Sockets Layer), or rather its newer and more secure successor TLS (Transport Layer Security), is a cryptographic protocol designed to ensure secure communication over the internet. Its main tasks are:

1. Data Encryption: All data transmitted between the user’s browser and the website’s server (e.g. login credentials, personal data, credit card numbers) is encoded in such a way that it becomes unreadable to any third party attempting to intercept it.
2. Server Authentication: An SSL certificate confirms the identity of the server the user is connecting to. This provides assurance that you are communicating with the correct, authentic site and not a fraudulent copy (e.g. in a phishing attack).

How does it work in simple terms?

When you visit an SSL-secured site, your browser and the site’s server “negotiate” a secure connection. The server presents its SSL certificate, which has been issued by a trusted Certificate Authority (CA). The browser verifies the validity of that certificate. If everything is in order, an encrypted connection is established and “https” along with the padlock icon appears in the address bar.

Why Is an SSL Certificate Absolutely Essential for Your Website?

The benefits of having an SSL certificate cannot be overstated:

• User Data Security: This is the most important reason. You protect your customers’ sensitive information from being intercepted by hackers. This is critical if you process any personal data, logins, passwords — and especially payment data.
• Building Trust and Credibility: The padlock icon and “https” are a clear signal to users that you care about their safety. Sites without SSL are often marked as “not secure” by browsers, which deters visitors.
• Requirement for Online Stores and Payment Processing: If you run an e-commerce store, SSL is an absolute requirement of security standards (e.g. PCI DSS).
• SEO Benefits: Google has officially confirmed that HTTPS is a ranking factor. Sites with SSL can gain a small advantage in search results. Furthermore, Google Chrome and other browsers actively warn users about sites without HTTPS.
• Regulatory Compliance (e.g. GDPR): Although SSL alone does not guarantee full GDPR compliance, it is one of the basic technical measures required to protect personal data.
• Access to Modern Browser Features: Some newer browser features (e.g. geolocation, service workers for PWAs) are only available to sites running on HTTPS.

Types of SSL Certificates – Which One Should You Choose for Your Site?

SSL certificates differ in their validation level (the method used to verify the applicant’s identity) and their features. Here are the main types:

1. DV (Domain Validation) Certificates – Domain Validation

• How they work: The simplest and fastest to obtain. The Certificate Authority only verifies that the applicant has control over the domain for which the certificate is being issued (e.g. via email to the domain’s administrative address or by adding a DNS record).
• Best for: Ideal for blogs, small business websites and informational sites where the primary goal is to encrypt traffic rather than provide extensive identity verification of the company.
• Popular examples: Let’s Encrypt (free), Comodo PositiveSSL, RapidSSL.

2. OV (Organization Validation) Certificates – Organisation Validation

• How they work: They require more detailed verification. The Certificate Authority checks not only control over the domain, but also the legality and registration details of the organisation (company) applying for the certificate.
• What they provide: The name of the verified organisation is visible in the certificate details, which increases user trust.
• Best for: Companies, organisations and portals that want to additionally confirm their identity and credibility.
• Popular examples: Comodo InstantSSL, GeoTrust True BusinessID.

3. EV (Extended Validation) Certificates – Extended Validation

• How they work: The highest level of validation, requiring the most rigorous organisation verification process by the CA. This includes checking legal documents, company status and sometimes even a telephone call.
• What they provide: EV certificates were once distinguished by displaying the company name directly in the green browser address bar. Although most browsers have dropped this special visual indicator, the company name is still visible in the certificate details and provides the highest level of trust.
• Best for: Large companies, financial institutions and online stores with a high transaction volume — anywhere maximum trust and credibility are critical.
• Popular examples: Comodo EV SSL, DigiCert Secure Site EV.

Additional Certificate Types:

• Wildcard Certificates: Secure the main domain and an unlimited number of its first-level subdomains (e.g. *.yourdomain.com will secure blog.yourdomain.com, shop.yourdomain.com etc.). Available at DV and OV level.
• Multi-Domain Certificates (SAN/UCC): Allow you to secure many different domains and subdomains with a single certificate. A very flexible solution.

Paid vs. Free Certificates (e.g. Let’s Encrypt) – Which Should You Choose?

Let’s Encrypt – Free SSL for Everyone

Let’s Encrypt is a non-profit initiative that revolutionised the market by offering free DV-type SSL certificates.

• Advantages:
  • Free: No purchase costs.
  • Automation: Easy installation and automatic renewal (certificates are valid for 90 days) using tools such as Certbot or through the hosting control panel.
  • Widely supported: Most hosting providers offer integration with Let’s Encrypt.
  • Sufficient for many sites: Provides the same level of encryption as paid DV certificates.
• Disadvantages:
  • DV only: Does not offer OV or EV certificates.
  • No warranty/insurance: Paid certificates often offer financial guarantees in case of a security breach caused by a CA error (though this is rare).
  • Short validity period: Requires more frequent renewal (although this is automated).

Paid SSL Certificates

• Advantages:
  • Choice of validation level: Access to OV and EV certificates, which build greater trust.
  • Financial guarantees: Offer a certain level of insurance.
  • Technical support: Usually better support from the Certificate Authority.
  • Longer validity period: Typically 1–2 years, meaning less frequent renewal (though it still requires attention).
  • Wildcard and Multi-Domain options: Often more comprehensive.
• Disadvantages:
  • Cost: Prices range from a few dozen to several thousand pounds/euros per year, depending on the type and provider.

Recommendation:
For most blogs, small and medium-sized business websites and informational sites, a free Let’s Encrypt (DV) certificate is more than sufficient and is an excellent choice. If you run a large online store, a financial institution or process highly sensitive data and want to maximise your credibility, it is worth considering a paid OV or EV certificate.

How to Install an SSL Certificate on a WordPress Site?

The installation process may vary depending on your hosting provider:

1. Automatic Installation via Hosting Control Panel: Many providers (e.g. Hostinger, SiteGround, Kinsta) offer easy one-click Let’s Encrypt installation in the admin panel (e.g. cPanel, DirectAdmin). This is the simplest method.
2. Manual Installation (for advanced users): Requires generating a CSR (Certificate Signing Request), purchasing/obtaining a certificate from a CA, and then installing it on the server.
3. WordPress Plugins (e.g. Really Simple SSL): After installing the certificate on the server, plugins such as “Really Simple SSL” can help configure WordPress to work correctly with HTTPS (e.g. redirects, fixing mixed content). However, the plugin itself does not install the certificate on the server — that must be done by the hosting provider or by you.

Key steps after SSL installation:

• HTTP to HTTPS Redirect: Make sure that all requests to the HTTP version of your site are automatically redirected to HTTPS (301 redirect).
• Fixing “Mixed Content”: Make sure that all resources on the site (images, scripts, styles) are loaded over HTTPS. Loading resources via HTTP on an HTTPS page causes “mixed content” errors and can “break” the padlock.
• Updating Internal Links: Make sure internal links point to HTTPS versions.
• Updating Google Search Console and Google Analytics: Add a new property for the HTTPS version and set it as the preferred one.
• Updating the sitemap (sitemap.xml).

Summary: SSL – A Small Padlock, an Enormous Difference

An SSL certificate is no longer an option — it is a fundamental element of every modern and secure website. Whether you choose a free Let’s Encrypt certificate or a paid OV/EV certificate, ensuring encrypted communication and server authentication is essential for protecting your users’ data, building trust and maintaining a good online reputation. Without an SSL certificate, you will also be unable to configure your site with HSTS security headers (more in this article).

At DosGatos.RED we make sure that all the sites we build are properly secured with an SSL certificate from day one. If you have questions about SSL or need help implementing HTTPS on your existing site, contact us!

Frequently Asked Questions (FAQ) – SSL Certificates and HTTPS