Write pseudocode for the password guessing algorithm, Computer Network Security

Assignment Help:

Write Pseudocode for the password guessing algorithm:

Consider the following authentication protocol:

Client

Transmission

Host

Explanation

U, user

U à

 

I am user U

 

ß {n, DES, SHA-1}

n, random challenge, DES, SHA-1

- I have SHA_1(P(U)), where P(U) is password of user U

 

- Here is a random challenge n, please use DES and SHA-1 to generate a response

r=DES(n, SHA-1(P))

U, rà

 

Response r is the encryption of the hash of the password P of user U using key n, DES for encryption, and SHA-1 for hashing.

 

 

ß yes/no

Compare: DES-1(n, r) to SHA_1(P(U))

Can the password of user U be obtained by using an offline password guessing attack? If your answer is yes, describe the attack and write pseudocode for the password guessing algorithm.  If your answer is no, describe why the protocol is resistant to an offline guessing attack.

2) Using RSA, perform an encryption then a decryption of the message M=5 using p=3, q=11, and e=7. (please add explanation, Show all your work, not just the final answer.)

3) You are the designer of a password security policy that requires passwords to expire once they have a probability of 0.001 of being guessed.  A potential attacker can test 1,000,000 passwords per second. If you chose passwords to be alphanumeric ("A" through "Z", "a" through "z", and "0" through "9"), what would you have to set the maximum lifetime of a password to in order to meet the required guessing probability (represent in days)?Assume the password size is 9 characters.


Related Discussions:- Write pseudocode for the password guessing algorithm

Write a note on digital signature, Question 1 Explain the types of threats...

Question 1 Explain the types of threats (Attacks) Question 2 What are the Characteristics of Good Encryption Technique? Question 3 Write a note on Digital Signatur

What is the maximum achievable data rate, Question: a) How many bits pe...

Question: a) How many bits per second can be sent on a noiseless 4 MHz channel if four-level digital signals are used? b) If a binary signal is sent over a 3 KHz channel who

What you understand by the term brute force attack, Question: a) Expla...

Question: a) Explain what you understand by the term brute force attack, giving an example of such an attack b) Briefly outline the concept of Caesar cipher and identify a

How an attacker can effectively de-layer and analyse data, Around the globe...

Around the globe the bank controlled Co-ops (Visa, MasterCard, Discover, and American Express) have rolled out millions of smart cards under the EMV (Europay, MasterCard, VISA) sta

Evaluate the percentage availability of the network, QUESTION a) "Two ...

QUESTION a) "Two of the key attributes of an enterprise network is that it have to be multi-platform and multisite." Decribe what you understand by this statement. b) A

Explain the close procurement project process, Question 1: Why do we ne...

Question 1: Why do we need a Law of Contract? a Explanation Reasons to have a law of contract b Explain the close procurement project process - Explanation (causes,

Technology, how can you enter the ASVAB practice test on line?

how can you enter the ASVAB practice test on line?

Explain the basic network topologies, Question: (i) ‘Implementation' is...

Question: (i) ‘Implementation' is a critical stage of the Systems Development Life Cycle. Show the four approaches which are commonly used to implement information systems in

Illustrate the term file carving, QUESTION (a) Illustrate the term fil...

QUESTION (a) Illustrate the term file carving. (b) What are the basic three main techniques for image steganography? (c) Distinguish between vector graphics and raster

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd