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

Assignment, Hello i have submitted an assignment and i am still waiting to ...

Hello i have submitted an assignment and i am still waiting to know if it has been accepted or not the ref number is TicketID: EM201381BRY525CN, the due date is for monday 27th of

Explain the random key distribution, Q. Explain the random key distribution...

Q. Explain the random key distribution? The triple key management mechanisms ensure a better and complete security solution using the random key distribution mechanism. In this

What is meant by certificate revocation, QUESTION (a) Which PKI (Public...

QUESTION (a) Which PKI (Public Key Infrastructure) model is typically favored by business organization? (b) Give one possible use of the "extensions" field of an X.509 certi

Understanding a business model of a spammer, The first and foremost need of...

The first and foremost need of  any business is a role to perform for its client base, and for the spammer this will typically be the role of advertising products which, due to the

Network management system, Question (a) Draw a typical hybrid star-rin...

Question (a) Draw a typical hybrid star-ring topology paying attention to how the clients and switching hubs are connected. (b) State 3 main differences between a router

Venn Diagram Problem, Students were asked about search engine they used.90 ...

Students were asked about search engine they used.90 of them said they used google chrome,70 used Internet Explorer,40 used Mozilla Firefox,30 used Google Chrome and Internet Explo

Algorithm, algorithm on simple intrest

algorithm on simple intrest

Nyquist capacity theorem, (a) Illustrate what you understand by Nyquist Cap...

(a) Illustrate what you understand by Nyquist Capacity Theorem? (b) Consider we wish to transmit at a rate of 64 kbps over a 4 kHz noisy but error-free channel. What is the mini

Briefly list functions of a public key infrastructure, Question: (a) Wh...

Question: (a) What is the major problem with public key encryption when compared to symmetric key encryption? (b) Consider the following protocol for communication between t

Using icmp reachability, USING ICMP TO TEST REACHABILITY:  ICMP can a...

USING ICMP TO TEST REACHABILITY:  ICMP can also be used to test several tools. An Internet host A, is reachable from another host B, if data packets can be send from A to B. P

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