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

ITC 571 Emerging Technologies and Innovation Assignment, Ask quProject brie...

Ask quProject brief template The project brief is a document upon which the full Project Proposal and Plan will be based. About me: Who are you? What do you do? What is your Exper

Operation of the signature based intrusion detection system, Question : ...

Question : (a) State whether the following statement is FALSE or TRUE: It is always better to have various access points to the Internet so that if a hacker takes one down you

Calculate the minimum sampling rate, QUESTION An analog sensor is used...

QUESTION An analog sensor is used to monitor the temperature of sea water at different depth. The sensor is fitted to a buoy and incorporates a wireless transmitter that send

Ip datagram, IP DATAGRAM Various options can be included to IP header,...

IP DATAGRAM Various options can be included to IP header, e.g., source route, record route and timestamp. Header with no function has H. LEN field value 5; data starts immedia

Designing and coding of job search mechanism, Designing and coding of Job s...

Designing and coding of Job search mechanism: Project Title: FREEHIVE (Sep 2005- Nov 2006) Role             : Developer Domain         : Social Network Client

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

Information asset classification-risk management, Information asset classif...

Information asset classification-risk management A number of organizations have data classification schemes (for instance confidential, internal, public data). The classificat

Explain briefly the role of the physical layer, a) Calculate the CRC for th...

a) Calculate the CRC for the frame below: Frame: 1101011011 Generator: 10011 Message after appending 4 zero bits: 11010110110000 b) OSI refers to a system in which any

Explain the concept behind digital signature, Question: a) Differenti...

Question: a) Differentiate between ‘Gross Settlement' and ‘Multilateral Net Settlement' providing suitable examples where necessary to support your answer. b) Differentia

Components of an information system, COMPONENTS OF AN INFORMATION SYSTEM ...

COMPONENTS OF AN INFORMATION SYSTEM The components of an information system are software, data, hardware, people, procedures and Networks. These 6 components are critical to ena

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