2nd Lecture

Venue: BK7, Building FTMK
Date : 22 -7-2009
Time: 9.00 a.m. – 10.50 a.m.

The lecture began today began at 9.00 a.m. sharp. Luckily, it was not begun with quiz like previous week, if not I will be fear to attend the lecture of this subject in future. Mr Zaki continued to teach us the second part of the first chapter. It began with the Sub-title “Security Attacks / Threats”. Basically, there are two types of attacks, they are passive attack and active attack. The examples of passive attack are release of message contents and traffic analysis; whereas the examples of active attack are Masquerade, replay, modification of message and denial of service.
After that, Mr Zaki explained about the methods of defense. There are six ways in order for us to deal with harm, they are prevent it, deter it, deflect it, detect it and recover. Then the types of controls are encryption, software controls, hardware controls, policies and physical controls. This chapter ends with the sub-topics Security Services and Security Mechanisms. The categories of security services are:

1. Authentication


2. Access Control


3. Data Confidentiality


4. Data Integrity


5. Non-Repudiation

Then, the two types of security mechanisms are Specific Security Mechanisms and Pervasive Security Mechanisms.
Soon after finished teaching chapter 1, the lecture continued with a very interesting topic – “Basic Cryptography”. Mr Zaki managed to teach the first part of this chapter only because of lacking of time. It started with a bit explanation about the Cryptography Concept, and we have been exposed with some terminologies in cryptography like plaintext, chiphertext, cipher, encipher, etc. There are two types of Cryptography Algorithms as depicted in the following diagrams:

1. Symmetric algorithms P=D(K,E(K,P))
   






2. Asymmetric algorithms P=D(Kd, E(Ke, P)

The two methods use in Cryptography Algorithm are Substitution and Transposition. This topic was very interesting because it is quite fun to find out the original message to be delivered behind the Ciphers sometimes. The earliest substitution cipher was invented by Julius Caesar during Gallic Wars. It is known as Caesar Ciphers. Then, Mr Zaki explained to us about the Simple Substitution Ciphers. Before the lecture ends, we were given a task. We were asked to decipher a cryptogram as shown below:
“YMJ KPJQ UWNHJ BNQQ NSHWJFXJ YT WH KTZW GD SJCY BJJP”
It took me some times to find out the original message. The answer I got is “THE FUEL PRICE WILL INCREASE TO RM FOUR BY NEXT WEEK”. The answer will be discussed in the following lecture, hope that my answer is correct… ….