TLS

What is TLS – Without Complicated Words

When you visit a website, especially if it involves payment, login or at least some kind of data input, you probably noticed a padlock in the address bar. It’s not just an interface decoration. This padlock means that the connection is secure – and most likely with TLS.

TLS is like a private channel between you and the website. Imagine that you are standing on a noisy street and want to pass important information to a friend. Shouting is a bad idea: everyone will hear. But if you have secret headphones connected only between you and him, that’s already safe. No one will get into the conversation, eavesdrop, change words along the way. This is how TLS works: it encrypts the entire exchange between your device and the server.

To make it even easier: TLS is an encrypted tunnel through which your passwords, cards, private messages walk. Without it, everything would be transmitted like a postcard — pretty, but in full view of everyone.

And what about HTTPS? It’s not an alternative to TLS — it’s an add-on. HTTPS is HTTP + TLS. So it’s not a separate technology, but just a name for the “regular” internet that’s protected by TLS. That’s why there’s a lock. Without TLS, it would just be HTTP — and there would be no guarantees of privacy.

The History of TLS: A Continuation of SSL, Only Better

To understand where TLS came from in the first place, you need to go back to the 1990s, when the Internet was noisy, modem-based, and insecure. Then Netscape stepped in and decided, “Stop sharing everything openly!” — and came up with SSL (Secure Sockets Layer). It was the first step towards a secure Internet.

The SSL 1.0 version never saw the light of day. Version 2.0 was released, but it quickly turned out to be full of holes. SSL 3.0, despite its ambitions, didn’t last long either, because technology was evolving and threats were becoming more sophisticated.

SSL was replaced by TLS in the early 2000s. It was no longer just an “update”, but an almost complete redesign with an emphasis on security, flexibility and speed. TLS has evolved since then.:

 • TLS 1.0 is the first version that inherits the principles of SSL.

 • TLS 1.1 is already safer, but still not perfect.

 • TLS 1.2 has become the gold standard for years.

 • TLS 1.3 is modern, fast, and secure. Everything is smart: a minimum of compromises.

Still, many people still call TLS “SSL”, just out of habit. As with the “flash drive”, which everyone calls USB, although this is the interface, not the media itself. Or like with “Xerox” instead of “copy machine”.

How TLS Works – In Simple Steps

The mechanics of TLS can look intimidating if you read technical descriptions. But in essence – it’s simple. Imagine:

1. You visit a website, the browser says to the server: “Hi! Let’s communicate securely. This is what I can do.”
2. The server responds:”Okay! I can do it too, here’s my certificate – see if it’s fake.”
3. The browser checks the certificate, it checks with trusted certification authorities. If everything is clean – we go further.
4. The “handshake” (TLS handshake) begins, both participants agree on the rules: what cipher to encrypt, what keys to use.
5. A secret key is established, it’s like you and a friend agreeing on a password to “lock” every email you send.
6. Everything is ready: encrypted communication begins, anyone who eavesdrops will only get a meaningless set of characters.

However, TLS not only encrypts, but also guarantees the integrity (no one changed the data along the way) and authenticity (you’re definitely connected to the intended recipient).

Certificates and Encryption: What Kind of Documents Are Inside TLS

TLS doesn’t work without so-called certificates. These are digital documents that confirm that a website is indeed who it claims to be. They are issued by special organizations called Certificate Authorities (CAs).

An analogy: You visit a company’s office, and the security guard has a badge with a photo and signature on his chest.

You look at the badge and see that the face matches, it was issued by the company, and you can trust it. Similarly, in this case.

The certificate contains:

• the site name;
• the expiration date;
• information about the company;
• the certification center’s signature.

 However, there are some nuances. There are three types of certificates, and here’s how they differ:

1. DV (Domain Validation) – Basic Level
   • Checks if a person owns a domain.
   • Fast and affordable.
   • Suitable for blogs, portfolios, and basic websites.
2. OV (Organization Validation) — Medium level
   • The organization is additionally verified: its registration, legality.
   • Used in commercial projects, corporate websites.
3. EV (Extended Validation) — Maximum level of trust
   • Multi-stage verification of a legal entity.
   • It is this certificate that gives the “green bar” in the browser.
   • Used by banks, payment systems, large companies.

Important: certificates do not encrypt on their own, they only participate in the process of establishing a secure connection. It’s like showing your passport at the border to gain trust. Then, there’s verification and control, and if everything is fine, you can proceed.

Where TLS Works – And Why It’s More Than Just The Web

If you think TLS is only for websites – you’re in for a surprise. TLS works not only in the browser, but literally everywhere where data goes over the internet and security is important.

 Here’s a list where TLS saves the day:

• Email – Gmail, Outlook, ProtonMail. When you send an email, TLS protects it from being intercepted along the way.
• Messengers – WhatsApp, Telegram, Signal. Yes, they have their own end-to-end encryption, but the transport itself is often protected by TLS.
• Banking apps — every time you make a transaction, your request is encrypted so that no one can see how much you’re transferring or to whom.
•  APIs and backend services — all these invisible channels for data exchange between apps and servers are also protected by TLS.

Imagine TLS as an invisible bulletproof vest for all your online activities. And you don’t notice it as long as everything works. It activates automatically when you visit a secure website, update a banking app, or send a request from a CRM to a cloud service. There are no pop-ups or “agree/disagree” buttons. It happens in the background, but without this background, you’d feel like you’re in the open field without a shield.

TLS Attacks: Why Even “Encryption” Has Holes

No technology is perfect. TLS is cool, but it’s not magic. In recent years, hackers have repeatedly found vulnerabilities, especially in outdated versions or poor implementations.

 Here are some notable vulnerabilities that have shaken the world:

• BEAST (2011) targeted TLS 1.0, allowing cookies to be decrypted in some cases.
• POODLE (2014) — found a loophole in SSL 3.0. Yes, it’s no longer TLS, but due to compatibility, the attack could still work on newer systems.
• CRIME and BREACH exploited data compression in TLS to extract sensitive information.
• Heartbleed (2014) — a real disaster. A vulnerability in the popular OpenSSL library allowed anyone to extract anything from the server’s memory, including passwords, keys, and private data.

Since then, the industry has drawn conclusions:

• TLS 1.0 and 1.1 are considered unsafe and are no longer supported in browsers.
• Administrators are updating OpenSSL en masse and disabling everything deprecated.
• Certificates are now checked more strictly, and non-trusted CAs (like the old WoSign) are no longer on the whitelist.

Important: TLS itself is a solid structure, but if it’s misconfigured, not updated, or trusted with fake certificates, it becomes a paper armor. If you are interested in DDoS attack mitigation you can check our article.

TLS Today: Why It’s Already a Standard with No Alternatives

Once upon a time, TLS was an “option” that was only enabled on payment pages. Today, it’s a mandatory standard, and you can’t do anything on the internet without it.

 Here’s how the situation has changed:

• All modern browsers require at least TLS 1.2. If a site uses something outdated, you’ll get a scary warning, as if you’ve entered a phishing page.
• The emergence of Let’s Encrypt completely turned the market upside down. Previously, an SSL/TLS certificate cost $100-300 per year. Now, it’s free, in a minute. No joke.
• Google and other search engines lower the ranking of sites without HTTPS. Without TLS, you’re an outsider.

In addition, TLS is not only about security, it is:

• a way to protect logins and passwords;
• a way to confirm that you are connecting to the correct site (and not a fake one);
• protection against data substitution: what you sent, the server received.

Without TLS, modern banking, authorization, API integrations, cloud services are impossible. It’s like trying to build skyscrapers without concrete.