SSL Certificates - from the "big bang" of information security to the present day
Tags: ssl, hosting, sslcertificate
Published: 2024-04-07 19:25:13

So much is to be said about SSL certificates, their meaning and application in the field of information security. Tailored to your needs, the FastFox team offers you a brief immersive encyclopedia on these so-called "encrypted safeties". Just in case. 

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/vt7chopkblhrlwwb47c8.png)

In this article you will learn what SSL certificates are, how and where they appeared, what changes in the work with certificates have occurred over time, what types of SSL certificates there are, how they work and what encryption centers are needed for.

## Let's start with a definition

An SSL Certificate is a digital file that is used to secure the data transmitted between a user and a website. An SSL Certificate can be compared to a lock on the door of your home that protects your privacy and property from intruders.

Let’s consult with our technical director to learn more! 

> - Hey Ivan, tell us, is an SSL certificate a code? How to visualize it?

> - An SSL Certificate is not a code. It is a file that contains digital information about the security of a website. Visually, an SSL Certificate appears as a text document or a file with a .crt or .pem extension. You can open it in a text editor and see various information such as organization name, domain name, serial number, expiration date, public key and digital signature of the certification authority.

But how did these certificates come into our lives and why are they so important? 

## The beginning of the story

The history of SSL certificates began around 1994, when Netscape Communications developed the Secure Sockets Layer protocol. This protocol was the first step towards creating a secure connection on the Internet and protecting data from unauthorized access. 

With the advancement of technology and the increase in online threats, SSL certificates have become a standard element required for all websites, especially those that share sensitive and personal data.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/w5wwf5v330m52qbnpmjn.png)

However, previously the process of obtaining and installing SSL certificates was complicated and required some knowledge and effort. With the advent of convenient services and Certificate Authorities (CAs), the process of obtaining an SSL certificate has become simpler and more accessible to all users. 

## Certification Centers

Certificate Authorities (CAs) are organizations that issue SSL certificates. When a user accesses a secure site (via HTTPS), their browser checks the SSL certificate that was issued by the CA. If the certificate is valid and signed by a trusted CA, the browser displays a green padlock or lock icon, which guarantees a secure connection.

> - Ivan, can you tell us who ultimately issues SSL certificates, the hosting provider or the certificate authority itself?

> - SSL certificates are issued by Certificate Authorities (CAs), not hosting providers. Hosting providers can help you install an SSL certificate on your server, but the certificate itself must be obtained from a trusted certificate authority. This is necessary to ensure a secure connection between the server and the client, as the SSL certificate confirms the authenticity of the website and protects the transmitted data.

> - Thanks, Ivan! 

## Types of SSL Certificates

There are several types of SSL Certificates, which differ in their level of validation and purpose of use: 

1. **DV (Domain Validated)** - A certificate that confirms only ownership of a domain name;
2. **OV (Organization Validated)** - a certificate that, in addition to validating the domain name, also confirms the legal ownership of the organization;
3. **EV (Extended Validation)** - the highest level of validation, which requires additional procedures to confirm the legal identity of the organization;
4. **Wildcard SSL** is a certificate that protects not only one domain name, but all its subdomains as well;
5. **Multi-Domain SSL** is a certificate that allows you to protect multiple domain names within a single certificate. 

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/pai0i6p2feaolu62isbq.png) 

> - I’ve also heard about TLS certificates, why are they not included in this list? 
> - TLS (Transport Layer Security) is the successor to SSL (Secure Sockets Layer). TLS is designed to be a more secure and efficient version of SSL. The main difference between the two is that TLS is a more modern and updated protocol that fixes some vulnerabilities and improves the security of data transmission.
> - Are there any other successors to the protocol? 
> - Of course, while TLS remains one of the most common protocols for secure communication on the Internet, other protocols also play an important role in data protection and online privacy, to name a few: 
 
**1. DTLS (Datagram Transport Layer Security)** is a version of TLS designed to protect data transmission in the UDP protocol. DTLS provides the same encryption, authentication and data integrity as TLS, but is adapted for use with the UDP protocol;
**2. QUIC (Quick UDP Internet Connections)** is a new protocol developed by Google that combines TLS and UDP functionality to provide fast and secure data transfer. QUIC is a more modern and efficient solution for network security;
**3. IPsec (Internet Protocol Security)** is a set of protocols for the secure transmission of data at the network connection layer. IPsec provides encryption, authentication, and protection against retransmission of data at the IP layer.

## Principle of operation 

The principle of SSL certificates is based on Public Key Infrastructure (PKI) cryptography. 

Here's how it happens:

**1. Certificate Request:** The site owner or organization requests an SSL certificate from a Certificate Authority (CA). The request includes the public key and owner information;

**2. Authentication:** The CA verifies the legitimacy of the request and the authenticity of the domain owner or company. After successful verification, the CA creates a digital signature for the certificate;

**3. Certificate issuance:** The CA issues an SSL Certificate that contains the public key, owner information, and the CA's digital signature;

**4. Certificate Installation:** The site owner installs an SSL certificate on his server. The server can now use the public key to encrypt the data and prove its authenticity with the CA's digital signature;

**5. Data Encryption:** When a user accesses a website via HTTPS, their browser obtains the server's public key from the SSL certificate. The browser uses this key to encrypt the data that is sent to the server;

**6. Data decryption:** The server uses its private key (which corresponds to the public key in the certificate) to decrypt the data received from the browser. This ensures the secure transfer of information between the user's browser and the server.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/zhsj1ycafori6nho1usf.png)

## Relevance of SSL in our time

Purchasing an SSL certificate in 2024 remains critical for the following reasons: 

- Ensures the confidentiality of data;
- Confirms the authenticity of the website;
- Improves search engine rankings;
- Helps meet safety standards;
- Guarantees compensation in case of data leakage.

## Summary

Initially a "huge breakthrough", SSL Certificates have become a standard in threat protection and data privacy for all web resources. SSL certificates play a key role in ensuring a secure online space, they must be understood and maintained on all websites.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/cajwjucf1wen07h42cd1.png)