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

Spambot detection - spam mail, Spambot Detection: The  previous studie...

Spambot Detection: The  previous studies in this field  have focused on content and meta-content based features.  The main assumption in this area of spam detection of late is

Illustrate about tinysec protocol, Illustrate about TinySec Protocol T...

Illustrate about TinySec Protocol TinySec is implemented on the link layer and addresses security requirements of the resource staffed nodes in the WSN based on the link layer

Classification of networks, Computer networks are defined by four factors w...

Computer networks are defined by four factors which are as given below: 1) NETWORK SIZE: According to the size of networks. 1) Local Area Network ( LAN) 2) Wide Area Ne

Algorithm, algorithm on simple intrest

algorithm on simple intrest

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

Security clearances-information security, Security Clearances For a secu...

Security Clearances For a security clearance in organizations each data user should be assigned a single level of authorization indicating classification level. Before approachi

Systems development life cycle (sdlc)-information security, SDLC Systems ...

SDLC Systems development life cycle (SDLC) is process of developing information systems through analysis, design, investigation, implementation and maintenance. SDLC is called as

What do you meant by the term bastion host, Question : (a) What do you...

Question : (a) What do you meant by the term "Bastion Host"? What is its use? (b) "Hostile" Java applets will do undesirable actions. Mention two problems caused by Hosti

Data classification and management, Data Classification and Management C...

Data Classification and Management Corporate and military organizations use a several of classification schemes. Information owners are responsible for classifying information a

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

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