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What is Transport Layer Security (TLS)?

Transport Layer Security (TLS) is a cryptographic protocol designed to provide secure communications over a network. It’s used widely in applications like web browsing, email, and voice-over-IP (VoIP), ensuring data privacy and integrity by employing encryption, authentication, and message integrity checks.

Have you ever wondered how your private information stays secure when you’re shopping online or accessing your bank account? Much of this security is thanks to Transport Layer Security, or TLS for short.

TLS is a cryptographic protocol that provides end-to-end communications security over networks and is widely used for internet communications and online transactions.

It’s like a protective tunnel for your data when it’s on its way from your browser to a website’s server and back.

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How does TLS work?

TLS works by using a combination of symmetric and asymmetric encryption. This might sound technical, but let’s break it down into a digestible example:

When your browser (let’s call it Browser A) wants to connect to a website (Website B) securely, they need to agree on how to exchange that secret key to open the locked box. This is done through what’s known as a ‘TLS Handshake’.

The TLS Handshake: Your browser starts by sending a ‘hello’ message to the website you want to connect to, specifying the versions of TLS and the types of encryption it can support.

Website B responds with its own ‘hello’ message, selecting the highest version of TLS and the strongest form of encryption that they both support. It also sends its public key (a part of the key pair used in asymmetric encryption).

Browser A uses this public key to encrypt a ‘pre-master secret’ (a random number) and sends it back to Website B. Only Website B’s private key can decrypt this.

Both Browser A and Website B use this pre-master secret to compute the same ‘master secret’ independently, and this master secret is used to generate session keys for symmetric encryption, which is faster and less computationally intensive than asymmetric encryption.

Finally, Browser A and Website B exchange messages confirming that future messages will be encrypted with the session key, completing the TLS handshake.

With the handshake complete, Browser A and Website B can now exchange data securely using the session keys.

Easy Example

Imagine you want to send a secret message to a friend. You could put the message in a box and lock it. Now, the message is safe, but your friend also needs a key to unlock the box and read the message.

This is the basic principle of encryption – turning readable data (the message) into an unreadable format (the locked box) to protect it from prying eyes.

Bottom Line

So, next time you see ‘https://‘ and the padlock symbol in your browser’s address bar, remember that’s TLS working hard to keep your data safe.

In an era where online privacy and security are of paramount importance, it’s good to know protocols like TLS have got your back, safeguarding your data from potential threats.

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Kushal Azza

Kushal Azza

Kushal Azza is a Google Certified Analytics & IT Professional, Digital Content Creator, and Go-To Digital Marketer with an Engineering Degree. He has over a decade of experience solving tech problems, troubleshooting, and innovating digital solutions. Follow him on Twitter and LinkedIn.

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