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

Explain the usage of digital signature, a) Explain the contents of the Cost...

a) Explain the contents of the Cost Assessment. b) Various Documents are needed for Configuration Management. State three of them, and describe their importance. c) Given tha

Information asset classification-risk management, Information asset classif...

Information asset classification-risk management A number of organizations have data classification schemes (for instance confidential, internal, public data). The classificat

Architecture of www named world wide web, Write down short notes on the arc...

Write down short notes on the architecture of WWW which is World Wide Web. WWW which means The World Wide web or the web is a repository of information spread worldwide and rel

Example bus network , Ethernet is a commonly used LAN technology. It was di...

Ethernet is a commonly used LAN technology. It was discovered at EXROX PARC(Palo Alto Research Center) in 1970s.Xerox, Intel and Digital described it in a standard so it is also kn

Explain briefly the role of the physical layer, a) Calculate the CRC for th...

a) Calculate the CRC for the frame below: Frame: 1101011011 Generator: 10011 Message after appending 4 zero bits: 11010110110000 b) OSI refers to a system in which any

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 the encryption model or symmetric cipher model, With explain the en...

With explain the encryption model the help of diagram. Symmetric cipher model uses the secret-key or a single-key for encryption/decryption purposes. It employs a symmetric encr

Develop firewall rules, Question requires you to develop firewall rules bas...

Question requires you to develop firewall rules based on a fictitious organisation. Scenario: You work for a security-conscious company, xC-Cure, who develop encryption tec

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