Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Computer Engineering Expert

1. Alice and Bob are sending a message m to each other

a) Give one method to attain confidentiality for m.

b) Give one method to attain integrity but NOT confidentiality for m

2. Computer B needs a user name and password for every login. User A requires to log on over the Internet. One solution is to send in the user name and the password in clear text.

a) What is the security vulnerability of this solution?

b) Design a better solution. Draw the diagram only to describe message exchange and content of each message.

3. A stream cipher is used to encrypt. The plain text m1 is 10101010, the pseudo random k is: 01101011

a) What is the cipher text c1? (Demonstrate the whole mathematical steps)

b) If another plain text m2 11100010 is encrypted with the same pseudo random number k andgenerate cipher text c2, what useful information about m1 and m2 can you extract from c1 and c2? (Demonstrate the entire mathematical steps)

4. B receives a financial transaction request message m from someone claims to be A. The message is encrypted with a shared security key k which only A and B know. Suppose the encryption is absolutely unbreakable.

a) Can B be reasonably sure that message is generated by A? Why?

b) If B shows another person C that B could use the key k to decrypt the message, could C be reasonably sure that message is generated by A? Whey?

c) Design a different protocol so that when B receives a message m from the real A, both B and C could be reasonably sure that the message is indeed generated by A?

5. If the time to encrypt a message m using a 64-bit secret key k algorithm is T, use the big-O notation to answer the following problems:

a) How to decrypt the message with brutal force? What is the amount of time required?

b) If length of the key is doubled, what is the amount of time needed to decrypt message with brutal force? Why?

6. With CBC encryption, message blocks m1-m2-m3-m4 are encrypted into c1-c2-c3-c4. Now if a hacker intercepts cipher text and retransmits c1-c3-c3-c4, what would be the “plain text” blocks being decrypted into? (Demonstrate all detail calculations)

Computer Engineering, Engineering

  • Category:- Computer Engineering
  • Reference No.:- M91996

Have any Question? 


Related Questions in Computer Engineering

1 what general attributes do organizations seek in

1. What general attributes do organizations seek in candidates when hiring information security professionals across all positions? Prioritize the list and justify your ranking. 2. What are the critical considerations wh ...

1 what techniques can be used to reduce page table

1. What techniques can be used to reduce page table shadowing induced overhead? 2. What techniques can be used to reduce NPT induced overhead? 3. One of the biggest impediments to widespread use of virtual machines is th ...

Assume object x has one simple variable and two tables with

Assume object x has one simple variable and two tables with two and three columns respectively. What is the identifier for the variable and each column of each table? We assume that the simple variable comes before the t ...

Assume now that you have two friends that will help you

Assume now that you have two friends that will help you cook, and that you have a large oven that can accommodate all three cakes. How will this change the schedule you arrived at in Exercise 6.2.1 above? Exercise 6.2.1 ...

1 what is the maximum number of nodes possible in a binary

1. What is the maximum number of nodes possible in a binary tree with 5 levels? 2. Given the following binary trees: (a) Indicate all of the structure properties that apply to each tree: full, perfect, complete. (b) Dete ...

You want to decide whether you should drive your car to

You want to decide whether you should drive your car to work or take the train. You know the one-way distance from your home to your place of work, and the fuel efficiency of your car (in miles per gallon). You also know ...

1 list three types of autonomous systems ass described in

1. List three types of autonomous systems (ASs) described in the text, and make a comparison between them. 2. Explain the concept of hop count in RIP. Can you explain why no hop is counted between N1 and R1 in Figure 20. ...

If items are retrieved from a hash table with unequal

If items are retrieved from a hash table with unequal frequencies a gradual speed-up in retrieval can be obtained by shifting each item as it is retrieved one position closer to its original hash position by performing a ...

Database controlsbased on your research conducted earlier

Database Controls Based on your research conducted earlier in this unit, identify the types of controls that are available to mitigate some of the vulnerabilities, threats, and risks you identified in the Unit 5 discussi ...

1 can we have a data-transfer connection without a control

1. Can we have a data-transfer connection without a control connection in FTP? Explain. 2. Assume we need to download an audio using FTP. What file type should we specify in our command? 3. Both HTTP and FTP can retrieve ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen