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 do you understand by demilitarized zone, Problem 1: What does the ...

Problem 1: What does the SNMP access policy show? SNMP community diagram SNMP access policy Problem 2: Does there exist any formal functional specificat

Ring topology, RING topology all computers are connected in loop. A ring ...

RING topology all computers are connected in loop. A ring topology is a network topology in which every node connects to exactly two other devices, forming a single continuous pa

Describe the functionality of a router, QUESTION: (a) Explain, with the...

QUESTION: (a) Explain, with the aid of a diagram, a Star topology of a network of your choice. (b) Illustrate on the use of a MAN and give an example of one. (c) Describe

Security policies, implementing password policy in organisation

implementing password policy in organisation

Digital signatures, Digital Signatures Digital Signatures are encrypted ...

Digital Signatures Digital Signatures are encrypted messages which can be proven mathematically to be authentic. These are created in response to rising requirement to verify in

Packets and frames, PACKETS: Packet is a generic word that define to sma...

PACKETS: Packet is a generic word that define to small code of data. Packet have different format. Each hardware needs different packet format.  FRAME: A hardware frame or

Mastering the complexity of network system, To master the complexity one mu...

To master the complexity one must apply the given points. CONCENTRATE IN UNDERSTANDING THE CONCEPTS: Instead of details of wires used to connect computers to a specif

Ipv6 addressing, IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit...

IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit address adds network prefix and host suffix. An benefit of IPv6 addressing is that there is address classes i.e. prefix/s

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