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

What is the major security flaw of set, QUESTION (a) Discuss why it is ...

QUESTION (a) Discuss why it is considered more secure to use the SET (Secure Electronic Transaction) for e-commerce instead of using SSL (b) Describe how the dual signature

Define broadcasting , Broadcasting is the distribution of video and audio...

Broadcasting is the distribution of video and audio content to a whole audience via any audio or visual mass communications medium, but generally one using electromagnetic radiat

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

Nessus vulnerability, You see two IP addresses. The IP address 192.168.58.1...

You see two IP addresses. The IP address 192.168.58.130 is the one of Bt4. The IP address 192.168.58.133 has ports 135 and 445 open; which indicates that it is a Windows machine. S

Major difference between a virus and a worm, Question: (a) State wheth...

Question: (a) State whether the following statements are TRUE or FALSE. Justify your answer. i. A good site security policy will require that users use computer generated p

Classification of networks, Computer networks are defined by four factors w...

Computer networks are defined by four factors which are as given below: 1) NETWORK SIZE: According to the size of networks. 1) Local Area Network ( LAN) 2) Wide Area Ne

Calculate alpha and beta value caesar cipher, Task 1 a. Consider the t...

Task 1 a. Consider the table showing the relative frequencies of letters in English. Arrange the frequencies from largest to smallest, and make a cumulative plot, using Exc

Discuss the influence the commercial operations, Question: A regional p...

Question: A regional police force has the following corporate objectives: ? to reduce crime and disorder; ? to promote community safety; ? to contribute to delivering just

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

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