Cryptography - Intro

Before we talk cryptography, lets first see the difference between HTTP and HTTPS beyond definitions and abbreviations.

We all know HTTPS is more secured than HTTP. What does it mean ?

To understand this, lets take the scenario of interacting with websites by logging in or submitting sensitive information. So these data’s are transmitted over the internet in form of small units called data packets.

I ran a simple experiment. I submitted username and password through a form using both HTTP and HTTPS and captured it in the network traffic.

Over HTTP

You can see the username and password are transmitted as plain text. So if anyone on the network intercepts the data packet can see our data.

Over HTTPS

Now you can see that the username and password is unreadable as it is encrypted. So even if someone intercepts our data they cannot read or use it.

HTTPS uses SSL/TLS (Secure Sockets Layer / Transport Layer Security) to make this communication secure.

This is made possible by cryptography

The term cryptography comes from Greek

• Crypto means hidden or secret.
• Graphy means writing.

So, cryptography means “the art of hidden / secret writing”.

By default our senstive data’s exist in plain text when transmitted over a network. So this means anyone with access to the network can read it.

We can’t always stop someone from accessing our data, but we can make sure they can’t understand it

So this is what cryptography does, it transforms readable data into something ununderstandable.