Introduction to Encryption [Part 01] : Understanding the Basics

In today’s digital era, where vast information is stored and transmitted across networks, safeguarding data is crucial. Data breaches can cause serious problems from financial losses to reputational damages. Encryption is key to keeping digital data secure.

By implementing encryption techniques the right way, we can protect sensitive data from unauthorized access, a facet commonly referred to as confidentiality. Additionally, encryption ensures integrity and authenticity forming the foundation of modern data security practices.

Plain Text, Cipher, and Cryptographic Key

Let's start by understanding two important terms: plain text and cipher text.

Plain Text refers to any type of data that is human-readable and understandable. For example, if you have a message like “Hello, How are you?” it’s considered as plain text

Cipher Text on the other hand, is what you get after applying encryption techniques to plain text. It appears more random, scrambled, and makes no sense. For the same message “Hello, How are you?”, the cipher text might look like a completely different, random string of characters.

Now, let’s discuss Cryptographic keys. Cryptographic Key is a piece of information (a kind of secret code) used in the encryption and decryption processes. This key controls and defines the security of the process and should be kept safe among authorized parties to ensure the security of the data.

What is Encryption?

To put it simply, Encryption is a technique used to convert human-readable plain text data into a scrambled, unreadable form called cipher text. This process is reversible, meaning that the cipher text can be converted back into plain text through decryption. In simple terms, Decryption is the process of deriving the plain text back from the cipher.s

However, the encryption-decryption process is more complex than it seems. Let’s dive deeper. In diagram 01, I've provided a straightforward illustration of what occurs during encryption and decryption. The left side of the diagram depicts the encryption process, while the right side illustrates decryption.

Diagram 01: Encryption and Decryption Process

Let's break down the encryption and decryption processes.

Encryption Process

To initiate encryption, we input the plain text along with a cryptographic key into the encryption algorithm - which returns the cipher text as the output. This encryption algorithm follows specific rules and operations to transform the plain text into cipher text.

Cipher text, being in encrypted form, remains indecipherable even if accessed by unauthorized parties. This ensures the security of the data, which is the ultimate objective of encryption.

Decryption Process

Conversely, the decryption algorithm is the exact reverse function of the encryption function. It takes cipher text and the cryptographic key as the input and returns the plain text (please refer to the left side of diagram 01).

However, it's crucial to note a key point: for successful decryption, the key you provided to the decrypt function should be the exact key you provided to the encryption function when you encrypted the particular cipher text. If you fail to provide the same key, you may not be able to decrypt the message and obtain the original plain text.

In essence, encryption ensures that only authorized parties with the key can access the original message. Others are left unable to decipher the message from the cipher text.

Enough with the theories. In the next article Part 02, we'll explore how these principles are applied in real-world scenarios.