What is SSL? Understanding SSL and How it Works
Posted on January 20th, 2025
SSL (Secure Sockets Layer) is a security feature that creates an encrypted connection between a website and a browser. It helps protect sensitive information, such as personal details, credit card numbers, and login data, as it is sent online. Only websites with an SSL certificate, a digital document that confirms the site’s identity, can use SSL.
Setting up SSL is important for improving both the security and performance of your site. In this article, we will explain what SSL is, how it works, how it affects websites, and the steps to install an SSL certificate.
How Does an SSL Certificate Work?
SSL certificates protect data by using two types of encryption: asymmetric and symmetric. Asymmetric encryption uses two keys: a public key to encrypt the message and a private key to decrypt it. The private key can also encrypt messages, which can only be decrypted by the public key. Symmetric encryption, however, uses one shared key to both encrypt and decrypt the message.
Here’s a simple explanation of how these encryption methods work:
- The website owner buys an SSL certificate from a trusted Certificate Authority (CA) and installs it on their site.
- When a visitor goes to the site, the browser and server set up a secure SSL connection through a process called the SSL handshake.
- During this handshake, the browser requests the server’s SSL certificate and public key to verify the site’s identity.
- After the certificate is checked, the browser and server exchange keys to create a temporary shared key.
- This shared key is then used to encrypt all messages between the browser and server during that session, and it will only be valid for a short period of time.
Once SSL is set up, the website will be secure and the data will be encrypted. This means no unauthorized people can intercept the communication. You can tell if a website is using SSL by checking for a padlock icon in the address bar of your browser. Clicking on this padlock will show more details about the certificate, like who issued it and when it’s valid. Here’s what it looks like on Google Chrome:
If a website doesn’t use HTTPS, the browser will show a “not secure” warning.
Since browsers warn users about unsecured sites, it’s a good idea to install an SSL certificate to keep your site secure. This helps visitors know right away that your site is safe to use.
How Does SSL Relate to HTTPS?
URLs can start with either HTTP (Hypertext Transfer Protocol) or HTTPS (Hypertext Transfer Protocol Secure). These protocols control how the data you send and receive is transferred. Websites without an SSL certificate use HTTP, meaning data is sent in plain text, and anyone could potentially intercept it.
This becomes risky if the data includes sensitive information, as hackers could use it for crimes like data breaches, identity theft, or cyber extortion. When you install an SSL certificate, it ensures that data is sent in an encrypted form using HTTPS. These two technologies work together – you need both for a secure connection.
To check if a site is using SSL, look for the HTTPS in the web address. This means the site is using the secure protocol.
When and Why Is SSL a Must?
SSL is essential for websites that handle sensitive information like usernames, passwords, or credit card details. SSL encryption makes sure that only the person you want to receive the data can read it.
Here are some other benefits of SSL for your website:
- Authentication: SSL helps prove your website’s identity, making it harder for someone to pretend to be your site and steal information.
- Data Integrity: SSL ensures that the data sent between you and your visitors isn’t changed or tampered with during transfer.
- Trust: Using SSL shows visitors they can trust your website, which is especially important for eCommerce sites that handle transactions.
- PCI Compliance: If your site accepts payments, you must follow Payment Card Industry (PCI) rules, which require an SSL certificate.
Does SSL Impact SEO?
Google has mentioned that websites with an SSL certificate tend to rank higher than those without it, as long as other ranking factors are the same. Although SSL isn’t as important as other factors like having great content, Google is working to make HTTPS the standard for all websites.
Since nearly 99% of browsing on Google Chrome happens on HTTPS sites, having an SSL certificate could be the key to turning visitors into customers instead of them leaving your site. While installing an SSL certificate will help your website’s search ranking, the main reason to use it is to build trust with your visitors, with the SEO benefit being a nice bonus.
Different Types of SSL Certificates
There are different types of SSL certificates depending on how many domains they cover:
- Single-domain SSL certificates: These certificates protect just one domain and can’t be used for its subdomains.
- Wildcard SSL certificates: This type protects a domain and all of its subdomains.
- Multi-domain SSL certificates (MDC): These certificates cover multiple domain names and their subdomains.
- Unified Communications Certificates (UCC): This is a type of multi-domain certificate designed for websites hosted on Microsoft Exchange and Live Communications servers.
SSL certificates also vary based on their level of authentication:
- Domain Validation (DV SSL): These are the most affordable SSL certificates. To get one, website owners only need to prove they own the domain.
- Organization Validation (OV SSL): These certificates offer a higher level of validation because they require proof of a legitimate business or organization.
- Extended Validation (EV SSL): EV certificates provide the highest level of validation and are the most expensive option.
How to Add SSL to Your Website
Now that you understand SSL and its benefits, let’s go over how to install it on your website. While there are different ways to install an SSL certificate, the general steps are:
- Choose a reliable certificate authority: Pick a trustworthy SSL provider, like Let’s Encrypt, DigiCert, or Comodo.
- Generate a Certificate Signing Request (CSR): Use tools like Microsoft IIS, Apache, or cPanel to create a CSR. This file includes your public key, domain name, and organization details.
- Upload the CSR: Upload the CSR file to your chosen certificate authority. They will verify your details and issue the signed certificate.
- Install the certificate: After receiving the signed certificate by email, download and install it on your website’s server.
- Force HTTPS: To make sure all visitors use a secure connection, add a code snippet to your .htaccess file to redirect to HTTPS.
Alternatively, you can get an SSL certificate from your hosting provider. For example, Interserver includes a free SSL certificate with all their hosting plans, which is automatically installed on new domains, subdomains, and parked domains added to your account. If you want to install an SSL certificate on older domains, follow these steps:
- In your Panel, go to Advanced -> SSL.
- Choose the domain and click Install SSL.
Once installed, HTTPS will be enabled by default, and your site will have a secure connection for your visitors.
How to Force SSL in a WordPress Website
Getting started with SSL on WordPress is simple, especially with plugins like Really Simple SSL that take care of the technical details for you. After you’ve installed your SSL certificate, follow these steps to make sure your site uses HTTPS:
- Log in to WordPress and go to Settings → General.
- Find the WordPress Address (URL) and Site Address (URL) fields.
- Change both addresses from HTTP to HTTPS.
- Save the changes and check your site to make sure everything works correctly.
- Set up a 301 redirect to ensure all visitors are sent to the new HTTPS address.
Conclusion
SSL (Secure Sockets Layer) is a security protocol that ensures a safe connection between your website and its visitors. It encrypts all the information exchanged, so no one can steal sensitive data like login details or credit card numbers.
Adding an SSL certificate to your website boosts its security and can also help improve its ranking on search engines, potentially giving you an advantage over your competitors. In this guide, we’ve explained what SSL is, how SSL certificates work, and how to install one on your site. If you have any questions, feel free to leave a comment below. Best of luck!
FAQs
Is SSL free?
SSL certificates can be both free and paid. Free SSL certificates are available through services like Let’s Encrypt, which provide basic encryption for websites. Paid SSL certificates, offered by trusted Certificate Authorities (CAs) like DigiCert or Comodo, often come with additional features such as extended validation, warranty, support, and higher trust levels, especially for businesses handling sensitive data.
Can SSL protect against malware or hacking?
SSL primarily protects data during transmission by encrypting the communication between a website and its users. However, it does not directly defend against malware, hacking attempts, or vulnerabilities within a website’s server or code. While SSL ensures the privacy and integrity of the data exchanged, it cannot prevent malicious software or cyberattacks targeting other aspects of a website’s security. To protect against malware or hacking, other security measures like firewalls, antivirus software, and regular security audits are necessary.