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

Nstissc security model, NSTISSC SECURITY MODEL The NSTISSC Security Model ...

NSTISSC SECURITY MODEL The NSTISSC Security Model provides a detailed perspective on security. While the NSTISSC model covers the 3 dimensions of information security, it removes

Risk control strategies-risk management, Risk Control Strategies Once th...

Risk Control Strategies Once the ranked vulnerability risk worksheet has created, they should choose one of following 4 strategies to control each risk: •    Apply safeguards wh

Securing the network using a packet filter firewall, 1. Network Design ...

1. Network Design Design your network giving appropriate IP addresses for your hosts. Provide a topology and table showing your addressing scheme. 2. F i re wall po

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

Corresponding access control matrix, Consider a computer system with three ...

Consider a computer system with three users: Alice, Bob and Cindy. Alice owns the file alicerc, and Bob and Cindy can read it. Cindy can read and write the file bobrc, which Bob ow

Point to point transmission(ppp), Normal 0 false false fals...

Normal 0 false false false EN-US X-NONE X-NONE

Compare and contrast between block and stream ciphers, Problem 1 Solve ...

Problem 1 Solve the following Caesar cipher by showing your working: EM KIUM EM AIE EM KWVYCMZML Problem 2 Compare and contrast between block and stream ciphers, listin

What is mac address, MAC Address The address for a machine as it is id...

MAC Address The address for a machine as it is identified at the Media Access Control (MAC) layer in the network structure. MAC address is generally stored in ROM on the n

Application-based ids, Application-Based IDS Application-based IDS (AppI...

Application-Based IDS Application-based IDS (AppIDS) is an advanced version of HIDS. It examines application for abnormal events. The ability to view encrypted data is the uniqu

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