Symmetric Encryption Lab

Symmetric cryptography, also known as shared$-$key cryptography, is a method of encryption and decryption that uses the same secret key for both processes.

When performing symmetric encryption, there are a lot of options, each with different results. In this lab we'll look at the effect of different ciphers and modes of operation on the ciphertext. We'll also look at key derivation functions, padding and error propagation.

This lab will run on the bash kernel and we will rely on openssl for most of the work.

Locate the "USD$\_$logo$.$bmp$"$ file and copy it into to a working directory for the encrypted images you'll be generating.

First, let's check the version of openssl we are using. Type:

openssl version

OpenSSL $3\mathrm{.}0\mathrm{.}215$ Mar $2022($Library: OpenSSL $3\mathrm{.}0\mathrm{.}215$ Mar $2022)$

to see a list of all available ciphers type:

openssl enc $-$list

Before we can start encrypting, we need something to encrypt. You can create your plaintext using an editor or use the code model in the code cell below to create your file. Change the $"..."$ to your message. Make sure you use at least $100$ characters.

echo $"...">$ plain.txt

echo "May your future be filled with endless opportunity, continued growth, and impactful contributions to Cybersecurity." $>$ plain.txt

cat plain.txt