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

Computer Security, I have an assignment of Computer Security to submit. Wil...

I have an assignment of Computer Security to submit. Will you guys help me making my assignment???

Using icmp reachability, USING ICMP TO TEST REACHABILITY:  ICMP can a...

USING ICMP TO TEST REACHABILITY:  ICMP can also be used to test several tools. An Internet host A, is reachable from another host B, if data packets can be send from A to B. P

Explain what is a broadcast storm, QUESTION: (a) Ethernet has grown in ...

QUESTION: (a) Ethernet has grown in popularity in the recent years and is now used in LANs. Give three reasons for the success behind Ethernet. (b) Ethernet uses the CSMA/CD

Udp encapsulation, UDP ENCAPSULATION As given in the figure below, UDP...

UDP ENCAPSULATION As given in the figure below, UDP packet is included in IP datagram and the IP datagram is then attached in the Frame.

Ipv6 base header format, IPV6 BASE HEADER FORMAT: It has less informat...

IPV6 BASE HEADER FORMAT: It has less information than IPV4 message header. Next header shows to first extension message header. Flow label is partitioned into a TRAFFIC CLASS

Describe how a cellular network works, Problem 1 . Show various features of...

Problem 1 . Show various features of a 1G network Total three features for each feature of 1G Problem 2. Describe how a cellular network works with functional block diagram

Udp datagram format, UDP DATAGRAM FORMAT: It is given in the figure be...

UDP DATAGRAM FORMAT: It is given in the figure below:

Explain characteristics of associative memory networks, (a) Describe the pr...

(a) Describe the principal characteristics of associative memory networks? (b) Name the two basic types of associative memories and the differences between them. (c) Give an

Fragmentation format, FRAGMENTATION Fragmentation information is kept...

FRAGMENTATION Fragmentation information is kept in different extension header.  Every fragment has base header and fragmentation header. Whole datagram including original hea

Use the chinese remainder theorem to evaluate x, Use the Chinese remainder ...

Use the Chinese remainder theorem to evaluate x from the following simultaneous congruences: x ≡ 1 (mod 2); x ≡ 2 (mod 3); x ≡ 3 (mod 5). Calculate gcd(14526, 2568). (

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