Homework #1 Solution

Write a small report (do not exceed 2 pages), answering the following questions:




1. What is the difference between authentication and authorization?




2. What is public key cryptography? (read http://en.0wikipedia.org/wiki/Public-key_cryptography)?




3. Consider a distributed system that supports RSA keys for authentication.

For this purpose, you can use ssh on a Unix-based system. Normally, you login to the system using a password.

Describe the steps needed to login using public key cryptography. The general idea is the following:

1. Create a public/private key pair for yourself

2. Login to the server via ssh as usual and put your public key to the authorized_keys list

3. Log out and login again without entering a password

Note: In your report you should describe:

The details of the above listed steps (you can add more steps if you like)

The description of how authentication works (what the client does and what the server does, at a high level)