Chapter 6 Encryption and Password Cracking

What is the difference between transposition and substitution in cryptography? (Short essay, no more than one pages, please.)
List and discuss the symmetric key encryption algorithms based on algorithm and security level.
List and discuss the asymmetric key encryption algorithms based on algorithm and security level.
Summarize a few of the methods used to acquire passwords.
What are the positive uses for password-cracking utilities?
Part2: Grade (15 points)

TextBook2: Chapter 4:
4.1 Briefly define a group.

4.2 Briefly define a ring.
4.3 Briefly define a field.
4.4 What does it mean to say that is a divisor of?
4.5 What is the difference between modular arithmetic and ordinary arithmetic? 4.6 List three classes of polynomial arithmetic.