Question

Try to make it as simple as you can and explain as much as it needed.

1. Define Integrity and Nonrepudiation? (2 points)

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2. What are the differences between Stream Cipher and Block Cipher? (2 points)

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3. What is Access Control and why is it important? (2 points)

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4. Message Authentication Code ensures authentication or integrity or both? Justify and explain your answer. (3 points)

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5. What are the weaknesses of DES? Why triple DES is better than Double DES? (3 points)

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Answer 1

Integrity ensures a message or transaction has not been tampered with. Non-repudiation provides evidence for the existence of a message or transaction and ensures its contents cannot be disputed once sent.

The main difference between Block cipher and Stream cipher is that block cipher converts Converts the plain text into cipher text by taking plain text's block at a time. While stream cipher Converts the plain text into cipher text by taking 1 byte of plain text at a time. ... While stream cipher uses 8 bits

The goal of access control is to minimize the risk of unauthorized access to physical and logical systems. Access control is a fundamental component of security compliance programs that ensures security technology and access control policies are in place to protect confidential information, such as customer data.

The MAC value protects both a message's data integrity as well as its authenticity, by allowing verifiers (who also possess the secret key) to detect any changes to the message content