SSL Certificate: What It Is, Why You Need It and How to Get It

What is an SSL certificate? An SSL certificate is a kind of "document" for a website that confirms the authenticity of the domain and ensures a secure connection between the server and the browser. Technically, it proves that the specific resource truly belongs to the declared owner and uses the secure HTTPS protocol. In practice, a characteristic "lock" appears in the address bar, indicating that data transmission is encrypted and cannot be easily intercepted by attackers. The technological basis of this mechanism is cryptographic algorithms that allow encrypting user data (logins, passwords, bank card numbers) and protecting it from unauthorized access.

Suppose we break down the concept of SSL (Secure Sockets Layer) into simple components. In that case, we can imagine this security layer as a virtual "shield" that hides original messages from prying eyes. The more advanced TLS (Transport Layer Security) has replaced the classical SSL. However, the term "SSL" is still widely used today to refer to the entire category of certificates. The certificate itself contains a public key used for data encryption. When a user opens a page, their browser interacts with the server: during the so-called "handshake," the authenticity of the certificate is verified, after which a secure communication channel is established, and all data travels in encrypted form.

For website owners, understanding how SSL certificates work is crucial. A properly configured
certificate increases trust in the site and provides a smooth experience for visitors who are not afraid to leave personal information. In the modern internet, the importance of HTTPS resources is so high that search engines may consider the lack of protection as a factor that lowers page rankings. Additionally, in many browsers, sites without encryption are already marked as unsafe, which deters potential visitors.

What purpose of an SSL certificate?

The purpose of implementing an SSL certificate always comes down to two key aspects: protecting confidential data and increasing the level of trust in the resource. When a user enters their name, email, password, or payment information on your site, this data must be transmitted in encrypted form, inaccessible for interception.

An attacker can exploit network vulnerabilities, uncover unencrypted messages, and steal personal data without proper encryption.

However, the importance of SSL isn't limited to payment transactions alone. Setting up a secure connection provides significant benefits even if the project doesn't accept cards. HTTPS pages have a higher chance of ranking better in search results, and the mere fact of using a secure protocol positively affects reputation. Visitors often won't even continue browsing a site if they see a warning that the connection is unsafe.

Types of SSL certificates

Different types of certificates vary in the depth of verification, purpose, and number of domains covered. Below is a list that organizes the main options:

1. Domain Validation (DV). Involves simplified verification of domain ownership. Usually issued quickly, as it only requires confirmation that you control the specified address.
2. Organization Validation (OV). Includes additional verification of the legal entity requesting the certificate. Documents confirming company registration are required. Additionally, the user opening the site can see the organization's name in the certificate information, which increases trust.
3. Extended Validation (EV). The strictest option is where the certificate authority thoroughly checks the owner's legal status. Upon successfully issuing an EV certificate, some browsers display the company name next to the padlock icon.
4. Multi-Domain Certificate (MDC). It allows the protection of several different domain names with a single certificate. This saves budget and simplifies security management when running multiple sites at once.
5. Wildcard certificate. It covers the primary domain and all subdomains (e.g., blog.example.com, shop.example.com, etc.). This is convenient for large projects with a flexible structure where the number of subdomains can change quickly.

How to get an SSL certificate?

The process of purchasing or issuing an SSL certificate is usually straightforward but requires accuracy and following specific steps. In a basic scenario, it looks like this:

First, you need to determine which type suits you. If you own a small site or are launching an internet resource without complex validation, DV will suffice. For corporate needs, when reputation matters, stricter options — OV or EV are chosen. Choose a certificate authority after determining the required "level" of protection. This could be a central global CA (Certificate Authority) or a provider partnered with a certification center.

The next step is generating a CSR (Certificate Signing Request). This is a special request generated on the server where your private key is stored. The CSR includes information about the domain, the company (if extended verification is needed), and contact information. You then send this request to the certification authority, and they carry out the verification. For simple cases, validation may be done through domain ownership confirmation (e.g., by email or placing a specific file in the site's root). If an OV or EV level is requested, the verification takes longer as the authority checks legal documents, confirms the organization's existence in public registries, and so on.

When the verification is completed, the certificate authority issues the SSL certificate — an electronic file that must be installed on your server or hosting. At this stage, it's essential to configure the web server correctly, specify the path to the certificate, link it with the private key, and restart the services. Detailed instructions vary depending on the software (Apache, Nginx, IIS, etc.). If everything is done correctly, visitors will see "https" at the beginning of the line and a secure connection when entering the site's address in a browser.

An alternative way to get an SSL certificate is through automated services like Let's Encrypt. This is a free solution that simplifies the issuance and renewal process. The service operates through scripts that allow the system to automatically verify the domain and renew the certificate every 90 days. This option is ideal for blogs, small business sites, and educational platforms.

When switching to HTTPS, a few more things should be considered. First, it's advisable to set up a 301 redirect from the unprotected version (http) to the protected one (https), so that search engines and visitors don't land on the outdated page. Second, check for mixed content, where some site resources (images, styles, scripts) are still loaded via an unencrypted protocol. Such errors can lead to browser warnings or incorrect page displays. Third, update all internal links, canonical tags, and the sitemap if they point to the HTTP address. All this is aimed to enable encryption and make the transition to a secure connection as smooth as possible.

Conclusion

The modern internet demands that websites be functional, attractive, and safe for users. An SSL certificate is a central element of this strategy, allowing encryption of the connection, protection of user data, and creating a sense of reliability for visitors.

Whether running a significant corporate resource, selling goods in an online store, or maintaining a personal blog, having HTTPS is no longer a luxury but an industry standard that's hard to compete without. Choose the appropriate type of certificate, carefully issue the request, and thoroughly verify the installation. Then, any confidential information (including passwords, bank cards, and personal messages) will be reliably protected, and your project will gain additional benefits in the eyes of search engines and the audience.

FAQ

How to check if a website has an SSL certificate?

The easiest way is to look at the browser's address bar: if there's a padlock icon to the left of the website address, the site has an SSL certificate. You can also check the site's URL: if it starts with "https://" instead of "http://", the certificate is installed.

How to renew an SSL certificate?

Renewing an SSL certificate usually happens through the company from which you purchased it. You'll need to place a new renewal order and possibly go through verification again.

What is a certification authority (CA)?

A certification authority (CA) is an organization that issues SSL certificates. The CA verifies the website owner's authenticity and confirms that the site is safe to visit.

What is HSTS and how is it related to an SSL certificate?

HSTS (HTTP Strict Transport Security) is a mechanism that forces the browser always to use a secure HTTPS connection when accessing a site. HSTS works in tandem with the SSL certificate, providing an additional layer of security.