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

Network intrusion system, In this work a network intrusion system (package)...

In this work a network intrusion system (package) must implement based on high interaction honeypots. There are two honeypots with different platforms (ubuntu and windows server 20

Explain the close procurement project process, Question 1: Why do we ne...

Question 1: Why do we need a Law of Contract? a Explanation Reasons to have a law of contract b Explain the close procurement project process - Explanation (causes,

Draw the full network diagram, Problem (a) Below is a capture of an E...

Problem (a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. The second screen capture is from the data portion of the frame.

Name the various layers of the osi model, Problem (a) Name the various ...

Problem (a) Name the various layers of the OSI model. (b) Show, by means of a diagram, how  the TCP/IP  reference model  is different from the OSI-7 reference model? Why is

Draw the waveform for an asynchronous transmission, (a) Draw the waveform ...

(a) Draw the waveform for an asynchronous transmission with the given specifications: 8 data bits with value 11010001 (LSB listed first here), one parity bit (even), one star

Define secure socket layer (ssl), Secure Socket Layer (SSL) accepts a combi...

Secure Socket Layer (SSL) accepts a combination of asymmetric and symmetric (public-key) encryption to accomplish integrity, confidentiality, authentication and non-repudiation for

Designing and coding of job search mechanism, Designing and coding of Job s...

Designing and coding of Job search mechanism: Project Title: FREEHIVE (Sep 2005- Nov 2006) Role             : Developer Domain         : Social Network Client

Explain how ethernet deals with collisions, (a) Describe how CSMA/CD operat...

(a) Describe how CSMA/CD operates and explain how Ethernet deals with collisions. (b) Describe how the subsequent protocols work: i. ARP ii. DHCP iii. DNS iv. SMTP (c) The

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

Ip datagram, IP DATAGRAM Various options can be included to IP header,...

IP DATAGRAM Various options can be included to IP header, e.g., source route, record route and timestamp. Header with no function has H. LEN field value 5; data starts immedia

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