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

CS, Discuss how developers should apply the following countermeasures to im...

Discuss how developers should apply the following countermeasures to improve the security of their code:

Explain the terms used in network security, Question 1 (a) Explain b...

Question 1 (a) Explain briefly the following terms as used in network security: (i) Denial of service (DoS) attack (ii) Birthday attack (iii) DeMilitarized Zone

The effect the incident has on your business, QUESTION There are gener...

QUESTION There are generally five factors that will influence how you respond to computer security incidents- The effect the incident has on your business Legal issue

Secure routing protocols for wireless sensor networks, Q. Secure routing Pr...

Q. Secure routing Protocols for Wireless Sensor Networks? A secure routing information protocol enables effective implementation of authentication and integrity checking defens

Discuss a communication channel, Question An organization is planning t...

Question An organization is planning to connect its networks to the Internet. The network is located within a four story building. A web server supporting online sales is also

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

Distinguish between steganograhy and cryptography, Question: (a) Disti...

Question: (a) Distinguish between Steganograhy and Cryptography. (b) "Playfair cipher is more secure than Monoalphabetic cipher." Justify this statement. (c) Various ap

Wireless networks, Wireless Networks The origin of wireless networks a...

Wireless Networks The origin of wireless networks and their ubiquity in the technological environment poses a new type of exposure and vulnerability for network security. Cont

Why use an ids, WHY USE AN IDS? IDS prevent from problem behaviors by in...

WHY USE AN IDS? IDS prevent from problem behaviors by increasing the perceived risk of discovery and punishment. Detect the attacks and other security violations. Detect and at

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