HTTPS: designation, purpose, working principle

What is the HTTPS protocol? HTTPS protocol (HyperText Transfer Protocol Secure) is an extension of the traditional HTTP that ensures a secure connection between a website and a browser. In other words, it is a secure hypertext transfer protocol in which data is encrypted using a unique algorithm. When using HTTPS, every page the user loads sends messages to the server and back through an encrypted channel, protecting them from potential attackers.

The main role of HTTPS is to verify the authenticity of the resource and maintain the confidentiality of the information that the browser sends to the site and back. In traditional HTTP, interaction occurred in plain text, and anyone with access to the data transmission channel could intercept or alter the sent documents. When HTTPS is activated, SSL/TLS is applied—a special encryption mechanism using unique keys. One of them is stored on the web server, and the other is obtained by the client when requesting the page. This approach prevents third parties from obtaining the user's personal information.

Purpose of the HTTPS protocol

Digital environment security is one of the most critical tasks online project owners face. HTTPS guarantees that the data exchanged between the client and server remains private. The protocol protects against two key threats: eavesdropping and data tampering. First, the attacker cannot see the original message because encryption hides the content. Second, if someone tries to alter a transmitted data packet, the checksum will be broken, which will immediately be detected as an error, and the browser will warn the user.

The practical value of HTTPS is evident in many situations. For example, when entering passwords or payment card details, it is important to be sure that outsiders cannot read this confidential information. The same applies to any other personal data: logins, email addresses, phone numbers, etc. Additionally, the secure protocol provides confidence that the server being connected to truly belongs to the stated company or domain owner. For this, a certification mechanism exists in which a special authority verifies the site's authenticity and issues an SSL certificate.

How does the HTTPS protocol work?

The essence of HTTPS is that when a resource is loaded, the browser and the server "agree" on an encryption method. It is based on a set of encryption algorithms, particularly asymmetric encryption (RSA or another method) during the initial channel setup and symmetric encryption (AES or similar solutions) during the subsequent data transmission.
This process includes several sequential steps:

1. The browser sends the server a "ClientHello" message, indicating the TLS/SSL versions and supported ciphers.
2. The site responds with its own "hello," selecting the optimal algorithm from those proposed by the browser.
3. The server sends the public part of the certificate issued by a certification authority and the public key.
4. The client checks whether it trusts the certification authority (browsers have pre-installed root certificates). If everything is okay, the client side generates a "session key" for symmetric encryption and encrypts it with the server's public key.
5. The web server decrypts the received data with its private key, and secure transmission becomes possible.

It is worth mentioning the term "TLS," which is essentially a modern version of SSL, but the terms "SSL certificate" and "TLS certificate" are used interchangeably in common usage. Nothing changes in basic logic: the encryption and authentication principles remain the same. Once the connection is established, each request and response goes through the encrypted channel. Suppose a problem arises during certificate validation (e.g., it is expired, belongs to another domain, or does not match the requested address). In that case, the browser seriously warns about the security threat.

Advantages of using HTTPS

The main benefits of switching to a secure protocol are:

• Protection of transmitted information. Any data (passwords, payment details, personal information) is reliably protected from interception through encryption and integrity verification.
• Verification of website authenticity. The browser analyzes the SSL certificate, confirming that the resource is indeed what it claims to be. This increases trust in the platform.
• Increased visitor loyalty. Most modern browsers mark secure sites with a special icon in the address bar, signaling a safe connection.
• Positive impact on SEO. Search engines (including Google) prioritize projects operating over HTTPS, considering them more reliable and useful for visitors.
• Reduced risk of attacks. The secure protocol makes it harder for attackers and malicious actors to inject harmful code or redirect traffic to their resources.

Importantly, HTTPS is now considered not an optional feature but a basic internet standard. More and more websites are denied access to certain features or lose part of their audience if they operate only over HTTP.

How to enable HTTPS protocol on a website?

Implementing the secure protocol usually involves purchasing or obtaining an SSL certificate and correctly configuring the web server. There are different methods, but the general algorithm looks like this:

First, the type of certificate is selected: DV (Domain Validation), OV (Organization Validation), or EV (Extended Validation). Higher validation levels are usually chosen if the site owner is a large organization that values its reputation. Free certificates from Let's Encrypt or paid DV certificates, which only verify the domain name, are often sufficient for small portals and blogs.

Next, a CSR (Certificate Signing Request) is generated on the server. This document includes domain information, the future owner company (if applicable), and encryption parameters. After generating the CSR, it is submitted to the certification authority (CA).

Then, the authority checks that you truly control the specified site. This procedure may include placing a special file in the root of the resource or configuring a DNS record. For extended validation (EV), legal documents confirming the company's existence must be provided.

Once the verification is complete, the CA issues the SSL certificate. Now, you need to configure the web server (Apache, Nginx, IIS, etc.) by installing the received files: the main certificate, intermediate files (chain), and the private key, which should never be shared. The settings are usually added to the server's configuration files. Activating the TLS (or SSL/TLS) protocol is important, and ensuring it listens on the correct port (usually 443) is essential.

The site's operability should be tested after installing and restarting the web server. Online diagnostic services (such as Qualys SSL Labs) or simply visiting the page and checking for the padlock icon in the address bar can be used. The connection will be marked as secure if the certificate is correctly installed. Don't forget to set up a 301 redirect from old HTTP links to HTTPS so that search engines and users are not confused by different versions of the resource.
Also, it is very important to eliminate "mixed content," where some elements (scripts, fonts, images) are still loaded through an unencrypted channel.

Conclusion

In conclusion, the HTTPS security protocol has long moved from being an additional precaution to a mandatory standard for everyone who values security and wants to offer users a high-quality service. The protocol is based on an encryption system combining asymmetry and symmetry and strict certification guaranteeing site authenticity. Essentially, HTTPS is a powerful foundation for secure data exchange, effectively countering threats and shaping a positive
image of the site in the eyes of search engines and the audience.

FAQ

Can HTTPS fully protect against all types of cyberattacks?

HTTPS provides high security but does not guarantee complete protection against all types of cyberattacks. It does not protect against malware on the user's side or web application vulnerabilities.

What ports does HTTPS use?

By default, HTTPS uses port 443 to establish a secure connection.

What types of SSL/TLS certificates exist?

There are several types of SSL/TLS certificates, differing in their level of validation: Domain Validation (DV), Organization Validation (OV), and Extended Validation (EV). They provide varying levels of trust and security for websites.