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

State the fermat-euler theorem, Question: (a) Prove that every positive...

Question: (a) Prove that every positive integer n can be factorized into a product of prime powers. (b) State the Fermat-Euler theorem as needed in the RSA system. (c) Us

Perimeter network security system, Title: Perimeter Network Security System...

Title: Perimeter Network Security System Outline Requirements The University is based in Glasgow, and provides higher education services to its students and staff. It is loc

Compare and contrast the trust models-pgp, a. PKI and PGP are two methods f...

a. PKI and PGP are two methods for generating and managing public keys for use in protocols such as secure email. Compare and contrast the trust models for public keys used in PKI

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

Explain how ftp works, QUESTION (a) FTP is a protocol used for the de...

QUESTION (a) FTP is a protocol used for the delivery of files across networks. Explain how FTP works (support your answer with a diagram). (b) How does TCP perform the gi

Address masks, ADDRESS MASKS To identify receiver, network apply addre...

ADDRESS MASKS To identify receiver, network apply address mask to receiver address and calculate to network address in routing table. It can use Boolean 'and' to calculate the

Sending an arp message, Normal 0 false false false EN-U...

Normal 0 false false false EN-US X-NONE X-NONE

Plaintext, how to encryt the data in plaintext cipher

how to encryt the data in plaintext cipher

Computer forensic, discuss the merits and demerits of computers freezing

discuss the merits and demerits of computers freezing

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