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

Using Technology as Experience Framework, Write a two to three (2-3) page p...

Write a two to three (2-3) page paper in which you: Explain how the Web user interfaces help donors to make decisions. Relate the emotional thread demonstrated in the case study to

Describe privacy-protecting techniques, Question: a) What do you meant...

Question: a) What do you meant by Privacy? b) Name the four privacy violations. c) Often, aggregate information and anonymized information can be combined to identif

Cloud computing security infrastructure, i want to know about cloud computi...

i want to know about cloud computing server security infrastructure development process

Explain possible attacks on rsa encryption, Problem (a) Describe RSA a...

Problem (a) Describe RSA algorithm with an example. (b) Answer the following RSA encryption, given the values of the primes are: p = 17, q = 11 and choosing e = 7. (c)

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Secure a wireless network, Secure a Wireless Network WIRELES Most onli...

Secure a Wireless Network WIRELES Most online retailers provide some type of privacy statement. Many statements are long, and appear in small print, and many appear to be simi

Function of key secrecy and algorithm secrecy in security, What is the func...

What is the function of key secrecy and algorithm secrecy in security?  Algorithm Secrecy is explained as follows: ‘Algorithm secrecy’ is a method of keeping an algorithm

Explain how the diffie-hellman key agreement protocol works, (a) Using Fer...

(a) Using Fermat's theorem, find 3 201 mod 11. (b) Explain how the Diffie-Hellman key agreement protocol works and what its purpose and main properties are. Consider a Dif

Processing an incoming arp message, PROCESSING AN INCOMING ARP MESSAGE ...

PROCESSING AN INCOMING ARP MESSAGE When an ARP message reaches, the protocol specifies that the receiver must operate two basic steps. First the receiver finds the sender's add

What is an autonomous system, QUESTION 1: a) Differentiate between a r...

QUESTION 1: a) Differentiate between a routing protocol and a routed protocol. b) Describe any three design goals of Routing protocols. c) Lists some of the features shared

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