SSL encryption: secure data on websites

In modern conditions, the security of data and information in the global network is a fundamental factor. There are more and more malicious software and scammers on the Internet who carry out daily attacks on company services and websites.

SSL is a special encryption protocol that significantly increases the level of data transmission security. Using a special cryptographic encryption system for key exchange, the protocol increases the level of confidentiality and integrity of data transmission between the server and the client. All certificates can have different levels of protection, on which the overall functionality depends. At the same time, any choice of level guarantees the protection of transmitted data.

Why SSL is needed

Security certificates are used by all resources today. Even if the website is a regular blog or forum, without proper protection and a level of security, it will not be able to actively develop. The reason is simple – sites without HTTPS protocols block all modern browsers.

Today, SSL is used by millions of websites around the world to secure the information they transmit. Without it, it is impossible to organize the work of an online store and any resource where the user specifies confidential information or is forced to register. Using the protocol, all transmitted information is encrypted with special keys, and even intercepted data can be decrypted only if the keys are available.

An SSL certificate acts as a unique digital signature for a particular website. First of all, large financial companies, banks and international payment systems began to use it. However, it is now difficult to find a web resource that works without a security certificate. They try to avoid such sites, and the browser always warns of the potential danger of the transition.

Certificates contain a certain set of information:

  • The specific domain name that was used during checkout
  • Information about the person (company) that received the rights to use the certificate
  • The physical location of the owner
  • Expiry date
  • Information about the company that acts as the supplier

An SSL security certificate indicates that the domain name really belongs to a specific site or company, and the owner has full rights to use special keys to encrypt data.

What does certificate validation look like

A process can be thought of as a sequence of actions. The user or system accesses the site’s web server. It can be any action: almost everything you do on the site is an exchange of information, which requires a request to the server. The user’s browser requires authentication from the web server.

In response, the web server sends a copy of the SSL certificate to the browser, and the browser checks whether this certificate can be trusted: whether it has expired, who issued it, and so on. The closest analogy is checking a pass at the entrance to a business center.

If all is well and the certificate is trusted, the browser tells the web server that it has verified that it is trustworthy. The web server acknowledges this, returns the digital signature, and starts the SSL connection. The browser and server can now exchange information securely.

In place of the user and the browser, there may be some service and its server: the transfer of information between the site and another resource occurs almost according to the same principle.

Types of SSL Certificates

You can check the type of certificate on the site using a browser: click on the lock in the address bar and select the “Secure connection” or “Secure connection” option, depending on the browser. Next, we will describe what SSL certificates are.

Self-signed. Such a certificate can be generated by anyone on their server. But there is no benefit from it: it is considered trusted only by the server on which it was created. Everyone else does not know what organization issued the certificate, so browsers will warn users or restrict access to the resource. Do not use these certificates.

With domain validation. All other types that are listed here are issued by special organizations – certification authorities. Certification authorities, or CAs, generate a unique key pair for the site and issue a certificate. Such certificates will be displayed correctly, they are trusted by browsers, and their data is certified by the CA. But in order for the center to issue a certificate, it must first check the person who applied to it, so that it can make sure that the resource is not fraudulent.

The difference between the types is what exactly the center checks before issuing a certificate. The easiest option is domain validation, also known as Domain Validation, or DV. The SC verifies that the site’s domain name is real and the resource exists, but does not associate it with any company. This is a budget type of certificate, cheaper than others, and it is suitable for individuals or small companies.

Organization validation. The second option is Organization Validation, or OV. In this case, the certification authority checks not only the domain, but also the company to which it belongs. Based on the results of the check, it certifies that the company exists. This is an option for commercial sites, and only organizations can buy such a certificate.

For banks and online stores that work with user payments, a certificate of at least OV level is recommended. It is considered more trusted, as it checks, among other things, the existence of the company.

With extended validation. The most complex, expensive and trusted type: EV, or Extended Validation. To obtain such a certificate, you will need to pass an extended check at the certification authority, answer questions and provide some documents about the company. But the browser will separately mark sites with such validation: the padlock sign will be green, with the signed name of the company and the country of its registration. This type is used by corporations, large services that deal with payment data, some banks.

Special types. For sites with specific needs, there are separate types of SSL certificates. These are options that can be added to any of the three types of certificate above. For example, Wildcard – it is used for sites that have subdomains. The domain name in such a certificate has an asterisk, which is substituted for the subdomain name.

There is also an MDC – a multi-domain certificate, which is needed for resources with several domains and subdomains. For example, a company has several sites with different names: it can buy a separate certificate for each, or one MDC for all three. There are different subtypes of multi-domain certificates, the main ones are SAN and UCC.


An SSL security certificate has long been an important element of protection not only for online stores, but for all sites in general that involve interaction with users. Registration, leaving comments, adding new materials from visitors, not to mention online payment – all this requires encryption.

Search engines also require websites to use a secure connection. And users are becoming more and more attentive to the privacy of their data. The use of SSL is an easy way to gain user trust and eliminate any privacy concerns when transmitting information over the Internet.