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

Vigenere Cipher, What key which if used to encrypt the ciphertext again wou...

What key which if used to encrypt the ciphertext again would give back the plaintext (i.e. key is a weak key)? Define a formula for identifying weak keys for the cipher below (

What standards are to be applied, Government funding has been given to a un...

Government funding has been given to a university consortium establishing a repository of resources for school teachers. They have engaged you to develop a search facility for teac

Describe how a cellular network works, Problem 1 . Show various features of...

Problem 1 . Show various features of a 1G network Total three features for each feature of 1G Problem 2. Describe how a cellular network works with functional block diagram

Packet filtering firewall-stateless packet filtering, Stateless Packet Filt...

Stateless Packet Filtering Stateless or static packet filtering is the most straightforward kind of packet filtering that allows or disallows data transfer based on the addres

Define the term enterprise network, a) Define the term "Enterprise Network"...

a) Define the term "Enterprise Network". b) Briefly discuss the similarity and differences between a switch and a router. c) A company XYZ has been renting the 1 st Floor of

What type of rfid tag is more appropriate for ws-pass, Consider the followi...

Consider the following case study: In order to avoid criticisms of their existing manned road-toll payment system on its private road, WS-Pass has decided to adopt an automated

Potential risks to information systems, Information System Security 1. ...

Information System Security 1. Write about: a. Potential Risks to Information Systems b. Factors to be addressed for making information systems more secure 2. Write about t

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

Professional issues in information technology, Thinking ethically is diffic...

Thinking ethically is difficult without a background in moral philosophy. Asking people to embrace ethics without offering practical explanation of the efficacy of so doing, is a t

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