Chapter 8, Problem R1RQ

Program Plan Intro

Confidentiality:

When the original plaintext message cannot be determined by an attacker, who intercepts the cipher text-encryption, the message is said to be confidential.

Message Integrity:

When the receiver can detect whether the message sent is encrypted or not or was altered in transit, the property is said to be message integrity.

Explanation of Solution

Difference between message confidentiality and message integrity:

Some of the difference between message confidentiality and message integrity are mentioned below:

Message Confidentiality	Message Integrity
In message confidentiality, two or more hosts communicate securely, typically using encryption	In message integrity, the message transported has not been tampered with or altered
In message confidentiality, communication cannot be monitored (sniffed) by untrusted hosts and the communication between the two parties is confidential.	A message has integrity only when the payload sent is the same as the payload received.

Confidentiality without integrity:

“Yes”, one can have confidentiality without integrity as sending a message confidentially does not guarantee data integrity. Although when two nodes have authenticated each other, the integrity of a message between them could be compromised during the transmission of a message.

Integrity without Confidentiality:

“Yes”, one can have integrity without confidentiality as a message that is altered in transit and is detected might have been sent in plaintext and thus would not be confidential.