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

Udp encapsulation, UDP ENCAPSULATION As given in the figure below, UDP...

UDP ENCAPSULATION As given in the figure below, UDP packet is included in IP datagram and the IP datagram is then attached in the Frame.

Hardware trojan detection, how to form the trojan integrated cirucit and wh...

how to form the trojan integrated cirucit and what are the tools are used to simulate the ciruit to our system and how to pass it as input to the clustering algorithm to get the ou

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

Calculate the dynamic range of the 16-bit scanner, You are hired as a consu...

You are hired as a consultant to help design a digital library in which books are scanned and stored digitally and made available to users of the World Wide Web. Assume that the li

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

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

Ipv6 next header, IPV6 NEXT HEADER It is given in the figure below:

IPV6 NEXT HEADER It is given in the figure below:

Produce a packet from a wireshark capture, Question requires you to produce...

Question requires you to produce a pcap file from a Wireshark capture.  In addition, you must include a screen capture of Wireshark and some specific information regarding the fram

Describe the time limit problem, Problem: (a) Use a simple example to ...

Problem: (a) Use a simple example to explain what is meant by a finite state machine. (b) Describe the time limit problem in an interrupt-driven system. (c) A certain m

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