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

Management of classified data-risk management, Management of Classified Dat...

Management of Classified Data Management of classified data comprises of its storage, distribution, portability, and destruction of classified data. All information which is not

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

Encapsulation, ENCAPSULATION Network interface layer adds IP datagram ...

ENCAPSULATION Network interface layer adds IP datagram as data area in hardware frame. Hardware ignores IP datagram message format. Standards for encapsulation defines details

Explain how the framework will align to the model, MB Enterprise Systems Lt...

MB Enterprise Systems Ltd based in Mauritius is a company specialized in application development with Europe as the main customer base. The company has implemented CMMI and has rec

Ip Datagram, Size of Option field of an ip datagram is 20 bytes. What is th...

Size of Option field of an ip datagram is 20 bytes. What is the value of HLEN? What is the value in binary?

Wan architecture and wan service, MegaCorp INC. is a large manufacturing f...

MegaCorp INC. is a large manufacturing firm that operates 5 factories in Dallas, 4  factories in Los Angeles, and 5 factories in Albany, New York.  It operates a tightly  connected

Describe header fields present in a udp segment, Question (a) In relati...

Question (a) In relation to a TCP segment structure, provide the fields responsible for: i. Connection Management ii. Flow Control iii. Error Control iv. Reliable, in-order

Produce a pcap file from a wireshark capture, Question requires you to prod...

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

Explain the concept of zero knowledge proofs, (a) Describe the concept of ...

(a) Describe the concept of zero knowledge proofs. Give a practical example. (b) Explain how a one way hash function works. (c) What are message authentication codes? (d)

Describe the five-layer network using block diagrams, Problem 1: a) One...

Problem 1: a) One of the limitations of file processing systems is data inconsistency. Briefly explain with the help of an example what do you understand by this phrase. b)

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