YCN1 TASK 1: SYMMETRIC AND ASYMMETRIC ENCRYPTION LABS | 2026 Update

YCN1 TASK 1: SYMMETRIC AND ASYMMETRIC ENCRYPTION LABS


INTRODUCTION TO CRYPTOGRAPHY — D830

Lab 1.1 Securing email Communications
Lab 1.2 Securing Sensitive Financial Data


Course Instructor:

Western Governors University

July 14, 2026

,Table of Contents
A: Lab 1.1: Securing Email Communications............................................................................ 2
Creating the RSA Key Pairs....................................................................................................................... 2
Create Pasha's RSA key pairs on ZYWIN01..............................................................................................................................2
Sharing Pasha’s Public Key with Rina via email............................................................................... 4
Email Application................................................................................................................................................................................4
Saving Pasha’s public key onto Rina’s computer............................................................................4
Open the email containing the PublicKey attachment....................................................................................................5
Encrypt Rina’s file using Pasha’s public key..................................................................................... 5
Encrypt the file called creditCardInfo.txt................................................................................................................................ 6
Sending the encrypted file back to Pasha via email........................................................................................................7
Switching virtual machine to Pasha’s computer, ZYWIN01........................................................................................ 7
Final Step: Decrypting the File....................................................................................................................................................8
Challenges Encountered and Solutions.................................................................................... 10
Challenge 1: Creating the AES-256 Key in the Protected Location........................................10
Solution:............................................................................................................................................................................................... 10
Challenge 2: Transferring the Key Using SCP to ZYWIN02........................................................10
Solution:............................................................................................................................................................................................... 10
B: Lab 1.2: Securing Sensitive Financial Data........................................................................11
Generate a random key for use with AES-256-CBC encryption...............................................11
PowerShell Admin...........................................................................................................................................................................11
Securely transfer using SCP to ZYWIN02..........................................................................................12
Create Encryption Keys............................................................................................................................................................... 12
Grant read-only permission to Rina for finance.key on ZYWIN02...........................................14
Encrypt the finance report using the finance key..........................................................................15
Email financialReport.xlsx.enc to Rina...............................................................................................16
File Permissions...........................................................................................................................................17
Decrypt financialReport.xlsx.enc using Finance.key....................................................................17
Lab 1.2 Challenges...............................................................................................................................19
Challenge 1: Granting Read-Only Permission to User Rina.................................................................................... 19
Solution:............................................................................................................................................................................................... 19
Challenge 2: Decrypting the Encrypted Financial Report.......................................................................................... 19
Solution:............................................................................................................................................................................................... 19
References............................................................................................................................................... 20




Western Governors University: D830 / 1

, A: Lab 1.1: Securing Email Communications


Creating the RSA Key Pairs


Create Pasha's RSA key pairs on ZYWIN01
a. Navigate to the user folder for Pasha. See Figure 1

C:\Users\Pasha




Figure 1

b. Create a new RSA private key with 4096 bits labeled, “privateKey” (see Figure 2)

openssl genrsa -out privateKey.key 4096




Western Governors University: D830 / 2