Encryption vs. Decryption: A Basic Overview

This page explores the fundamentals of Encryption and Decryption and highlights the key differences between them.

As the internet becomes increasingly integral to our lives, facilitating everything from banking to business communication and governmental operations, the need to protect data transmitted over both wired and wireless networks is paramount. Encryption is the process of securing data to prevent unauthorized interception or decoding. Various security and encryption algorithms are employed in wireless communication systems such as GSM, CDMA, LTE, and Zigbee. For wired communication, AES and DES with 128-bit keys are commonly used.

Encryption Explained

At its core, encryption can be visualized as performing an EX-OR operation on the input data with a security key. This key is typically generated using a Linear Feedback Shift Register (LFSR). The LFSR is initialized with a vector, which can be user-defined or automatically programmed.

The encrypted output is then transmitted through the communication channel. Figure 1 illustrates a simplified encryption and decryption process using EX-OR and an LFSR.

Figure-1: Encryption Decryption Process

Decryption Explained

Decryption is essentially the reverse of the encryption process. The received encrypted data serves as input to an EX-OR operation. The key used for decryption is generated locally using an LFSR, utilizing the same initialization vector that was employed during encryption.