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

Arrangement of self-learning switches, QUESTION a) Consider the speed ...

QUESTION a) Consider the speed of propagation of an electrical signal is same to 2x10 8 m/s, evaluate the ratio of the propagation delay to the transmit time for the given typ

Keystroke-based access control model, Suppose you are working for one of th...

Suppose you are working for one of the leading credit reporting agencies that manages users' credit rating info with different financial institutions.  The company wishes to implem

Identified issues in networks, The "Big Red Rocks" (BRR) mining company is ...

The "Big Red Rocks" (BRR) mining company is based and operates in Western Australia. They are primarily an iron ore miner, but they also produce electricity through tidal power to

Explain rsa encryption, (a) Describe RSA encryption. (b) For an RSA encr...

(a) Describe RSA encryption. (b) For an RSA encryption the values of the primes are: p=29, q=31. select e=11, evaluate the public and private keys. (c) How can RSA be used fo

Incident response, Incident Response: Complete the following sections as id...

Incident Response: Complete the following sections as identified from your Incident Response template (in MS Word format): Update the table of contents (autogenerated) Separate

Effective legal and ethical frameworks, All references using actual quotes,...

All references using actual quotes, paraphrase, or specific arguments, should employ page numbers. The essay is based on the unit content and should engage with the set readings, a

Use the chinese remainder theorem to evaluate x, Use the Chinese remainder ...

Use the Chinese remainder theorem to evaluate x from the following simultaneous congruences: x ≡ 1 (mod 2); x ≡ 2 (mod 3); x ≡ 3 (mod 5). Calculate gcd(14526, 2568). (

Draw a suitable physical network diagram, Question a) From the capture ...

Question a) From the capture below: Give the datagram source IP address, upper layer protocol, Total length in decimal and header checksum in hexadecimal; the segment source po

Explain about structure of management information, Question 1 a) What is a...

Question 1 a) What is a NMS? Question 2 Explain about Structure of Management Information Question 3 A)In which UDP port number does a protocol entity receive message?

Tcp- reliable transport service, TCP-RELIABLE TRANSPORT SERVICE INTRO...

TCP-RELIABLE TRANSPORT SERVICE INTRODUCTION:  TCP is the major transport protocol architecture in the TCP/IP suite. It uses unreliable datagram function offered by IP whe

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