CST 311 Week 4

 

WELCOME TO WEEK 4

Learning Journal

This week was shorter than usual because we had the midterm. It really helped to have a lighter workload since it gave me more time to study and review for the test. The topic for this week was network security, which we briefly discussed in Chapter 1. However, in Chapter 8, we delved deeper into the principles of cryptography, focusing on how to provide confidentiality, integrity, authentication, and non-repudiation.

We began by understanding the language of cryptography, where keys are used to encrypt plaintext and decrypt ciphertext. We also discussed the differences between symmetric key cryptography and public key cryptography.

In symmetric key cryptography, both the sender and the receiver must know and use the same shared secret key. The challenge with this approach is that securely transmitting the key to the other party is difficult, especially if the parties have never met.

Public key cryptography, on the other hand, works differently. The sender and receiver do not share a secret key. Instead, there are two keys: a public key and a private key. The public key, known to everyone, is used for encryption, while the private key, known only to the receiver, is used for decryption. This method can also work in reverse, where the private key is used for encryption and the corresponding public key is used for decryption.

It’s also important to highlight the role of public key certificates in maintaining security. To avoid vulnerabilities such as man-in-the-middle attacks, public key certification is crucial. A certification authority (CA) binds a public key to a specific entity. This provides proof of identity and ensures that the certificate is tied to the correct key.