COSC 328: Lab #9 - Security
August 2nd , 2023
Introduction
In this lab, we will do some practice questions on security. This lab is intended to be completed in one lab
period.
i
1
Info: All work must be shown/documented for marks. This lab is due in electronic form and is to be
submitted by the end of the day on Friday, August 11th , 2023. Late assignments will not be accepted.
Security True or False (6 marks)
Answer the following true or false questions on security.
Question 1
(a) Nonce’s are often used to combat the playback attack.
(b) Two parties often use public-key encryption to agree on a shared one-time symmetric session key.
(c) Suppose an SSL session employs a block cipher with CBC (cipher block chaining - see p. 603).
The sever sends the IV (initialization vector) to the client in the clear.
(d) When using a MAC, the communicating entities need to have a shared secret key.
(e) In the SSL record, there is a field for SSL sequence numbers.
(f) Suppose certifier.com creates a certificate for foo.com. Typically, the entire certificate would be
encrypted with certifiers.com’s public key. True or false?
1
2
General Security Knowledge (12 marks)
Complete the following questions from Chapter 8 on general security knowledge.
Question 2
(a) R. 1 (p. 664) (3 marks)
(b) R. 3 (p. 664) (2 marks)
(c) R. 6 (p. 664) (2 marks)
(d) R.9 (p. 664) (1 mark - your answer must provide justification)
(e) R.10 (p. 664) (1 mark - your answer must provide justification)
(f) R.16 (p. 665) (1 mark)
(g) R.19 (p. 665) (2 marks)
3
Cryptography (6 marks)
The following questions focus on the use of cryptographic operations in key agreement and message exchange.
Question 3
(a) P. 10 (p. 667-668) (2 marks) (You should draw an image showing the transactions and clearly
indicate the messages.)
(b) P. 17 (p. 669) (2 marks) (This will be an image showing all the steps) (There is an error in the
question and you should refer to Figure 8.21 to answer this question (Figure 8.19 only offers
confidentiality)
(c) p. 18 (p. 669) (2 marks) - Justify your answers
!
Submission Details: This lab is due in electronic form via Canvas, by the end of the day on Friday,
August 11th , 2023. Late assignments will not be accepted.
2
COSC 328: Lab #9 - Security
August 2nd , 2023
Introduction
In this lab, we will do some practice questions on security. This lab is intended to be completed in one lab
period.
i
1
Info: All work must be shown/documented for marks. This lab is due in electronic form and is to be
submitted by the end of the day on Friday, August 11th , 2023. Late assignments will not be accepted.
Security True or False (6 marks)
Answer the following true or false questions on security.
Question 1
(a) Nonce’s are often used to combat the playback attack.
(b) Two parties often use public-key encryption to agree on a shared one-time symmetric session key.
(c) Suppose an SSL session employs a block cipher with CBC (cipher block chaining - see p. 603).
The sever sends the IV (initialization vector) to the client in the clear.
(d) When using a MAC, the communicating entities need to have a shared secret key.
(e) In the SSL record, there is a field for SSL sequence numbers.
(f) Suppose certifier.com creates a certificate for foo.com. Typically, the entire certificate would be
encrypted with certifiers.com’s public key. True or false?
1
2
General Security Knowledge (12 marks)
Complete the following questions from Chapter 8 on general security knowledge.
Question 2
(a) R. 1 (p. 664) (3 marks)
(b) R. 3 (p. 664) (2 marks)
(c) R. 6 (p. 664) (2 marks)
(d) R.9 (p. 664) (1 mark - your answer must provide justification)
(e) R.10 (p. 664) (1 mark - your answer must provide justification)
(f) R.16 (p. 665) (1 mark)
(g) R.19 (p. 665) (2 marks)
3
Cryptography (6 marks)
The following questions focus on the use of cryptographic operations in key agreement and message exchange.
Question 3
(a) P. 10 (p. 667-668) (2 marks) (You should draw an image showing the transactions and clearly
indicate the messages.)
(b) P. 17 (p. 669) (2 marks) (This will be an image showing all the steps) (There is an error in the
question and you should refer to Figure 8.21 to answer this question (Figure 8.19 only offers
confidentiality)
(c) p. 18 (p. 669) (2 marks) - Justify your answers
!
Submission Details: This lab is due in electronic form via Canvas, by the end of the day on Friday,
August 11th , 2023. Late assignments will not be accepted.
2