Help needed in a personal project concerned in : “Security network project”

This covers. :
- Secret key encryption
-Substitution cipher and frequency analysis
-Encryption modes , IV , and paddings
-common mistakes in using encryption
-programming using the crypto library .

*In this job there is 3 TASKS to be done * :
Task1 : Encryption using Different ciphers and modes
Task2 : Encryption Mode - ECB vs CBC
Task3 : Programming using the crypto library