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

Firewall analysis tools-information security, FIREWALL ANALYSIS TOOLS Th...

FIREWALL ANALYSIS TOOLS There are a number of tools automate remote discovery of firewall rules and assist the administrator in analyzing rules Administrators who feel wary of u

Illustrate the term file carving, QUESTION (a) Illustrate the term fil...

QUESTION (a) Illustrate the term file carving. (b) What are the basic three main techniques for image steganography? (c) Distinguish between vector graphics and raster

Data compression and the transport services, Da t a compre s sion a...

Da t a compre s sion and the trans p ort s e rvices,   The main purpose of the transport layer is to provide services which are efficient, reliable and cost-effecti

What is a firewall, QUESTION (a) Define and distinguish between Electro...

QUESTION (a) Define and distinguish between Electronic Commerce and Electronic Business (b) According to you what are the benefits that Electronic Commerce can brings to org

Non-repudiation and auditing, Proof that the sender forwards the message. I...

Proof that the sender forwards the message. It also prohibits the author of the code from falsely denying that he forward the message. This is achieved by record using the exact ti

Hashing, Hashing is the transformation of a string of characters into a g...

Hashing is the transformation of a string of characters into a generally shorter fixed-length key or a value that presents the original string. Hashing is used to index and retri

What is b-router, B-Router Hybrid devices that has the features of bot...

B-Router Hybrid devices that has the features of both routers and bridges . A bridge router or brouter is a network machine that acts as a router and as a bridge. The brout

Programming, SDES encryption and decryption

SDES encryption and decryption

Social studies, how would land elevation have canged if coronado had travel...

how would land elevation have canged if coronado had traveled 150 miles due west from what is today arizona instead of west toward new mexico

TCP/IP v OSI, What are the main differences between TCP/IP vs OSI?

What are the main differences between TCP/IP vs OSI?

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