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 operation of the matchmaker middle agent, Question 1: (a) E...

Question 1: (a) Explain the operation of the "matchmaker" middle agent. (b) Describe why broker middle agents are more efficient in terms of the time taken for a service to

Find the possible deciphering transformations, Question: (a) A string o...

Question: (a) A string of ciphertext was enciphered using an a±ne transformation of single letters in a 28-letter alphabet consisting of A to Z, a blank and a?, where A to Z ha

Base lining-information security, Base lining •    Organizations do not ...

Base lining •    Organizations do not have any contact to each other •    No two organizations are identical to each other •    The best practices are a moving target •    K

Define repeater, Repeater known as regenerator ; it is an electronic mac...

Repeater known as regenerator ; it is an electronic machine that performs only at physical layer. It gets the signal in the network before it becomes loss or weak, recreates the

What is triple key management scheme, Q. What is Triple Key Management Sche...

Q. What is Triple Key Management Scheme? The triple key management mechanism provides optimum security by enabling the use of two pre-deployed keys for each of the WS nodes, an

Cipher methods-cryptography, Cipher Methods There are 2 methods of encry...

Cipher Methods There are 2 methods of encrypting plaintext: • Bit stream method – every bit in the plaintext bit is transformed into a cipher bit one bit at a time. • Block cip

Describe benefits of effective communication, Question: (a) Explain the...

Question: (a) Explain the following terms: Information Communication Technology, Operating System and Application Software. (b) Define what a computer is, give four anatomi

Elliptic Curves, #questioAn elliptic curve y^2=x^3+ax+b(mod29) includes poi...

#questioAn elliptic curve y^2=x^3+ax+b(mod29) includes points P=(7, 15) and Q=(16, 13) a)Determine the equation of the crve b) Determine all values of x for which there is no point

Explain authentication process in a synchronous token system, Question: ...

Question: (a) Explain briefly the PCI Control Objectives which enterprises must meet to be compliant with the Payment Card Industry Data Security Standard (PCI DSS). Specify a

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