What does the presence of rx in message 2 assure

Assignment Help Basic Computer Science

Reference no: EM131088551

Consider the following protocol for Authentication/Key Distribution: (X and Y are two principals, A is a Certificate Authority or a Key Distribution Center, RX is a rand on number and EX means encrypted with the secret key of X.)

1. X→A: X, Y, RX

2. A→X: EX (RX, Y, K, EY (K, X))

3. X→Y: EY (K, X)

4. Y→X: EK (RY)

5. X→Y: EK (RY - 1)

(a) What does the presence of RX in message 2 assure?

(b) What problem will be created if an attacker were to break an old K (and the attacker has also copied messages for that session)? Explain your answer.

Reference no: EM131088551

Questions Cloud

Calculate the ratio of investments : Giving your answer in its simplest terms, calculate the ratio of investments of the three partners in the second year of trading. At the end of the second year of trading, Veera received £10,800 as her share of the profits.

Prove that the distributed commit problem is not solvable : Hint: Show a reduction from the consensus problem to the distributed commit problem.

Total cost of purchase and advise : Using a conversion of €1 = £0.72, compare the deposits, the monthly payments, and the total cost of purchase and advise Thomas on which company is cheaper.

Do these factor present an opportunity or threat to the firm : This section should provide an overview of the country with attention paid to the external factors that influence how business in conducted within the country. This includes assessing the economic, political, cultural, legal and technological fac..

What does the presence of rx in message 2 assure : What problem will be created if an attacker were to break an old K (and the attacker has also copied messages for that session)? Explain your answer.

Question regarding the employee paycheck : Name what is a system that requires an employer to automatically deduct income taxes from an employee's paycheck and send the deducted tax directly to the government.

Designing cryptographic protocols : For each, give an example where their principle applies and results in an improved protocol.

What advantages and disadvantages of each type of structure : What are the principal differences between functional and divisional organizational structures? What are the advantages and disadvantages of each type of structure? When do organizations appropriately use a functional organizational structure?

Identify the main communication problems boeing : 1. Identify the main communication problems Boeing is facing, the causes of the problems and the symptoms. 2. Identify the key stakeholder groups and discuss the issues that one or two stakeholder groups are concerned about.

User Account

All Pages