Buğra Gedik's Courses
@ Bilkent University

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.wikipedia.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:
   • Create a public/private key pair for yourself
   • Login to the server via ssh as usual and put your public key to the authorized_keys list
   • 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)