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

Public key infrastructure (pki)-cryptography, Public Key Infrastructure (PK...

Public Key Infrastructure (PKI) It is integrated system of software, encryption methodologies, protocols, legal agreements, and 3rd-party services enabling users to communicate

Fragment identification, FRAGMENT IDENTIFICATION: IDENT field in every...

FRAGMENT IDENTIFICATION: IDENT field in every fragment matches IDENT field in real datagram. Fragments from different datagrams may arrive out of order and still be saved out.

Professional issues in information technology, Thinking ethically is diffic...

Thinking ethically is difficult without a background in moral philosophy. Asking people to embrace ethics without offering practical explanation of the efficacy of so doing, is a t

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

Define byte stuffing, Sometimes the special character may see in data and a...

Sometimes the special character may see in data and as a part of data they will be misinterpreted as packet data. The solution to this cause is Byte stuffing.   In general to

The security systems development life cycle (secsdlc), The Security Systems...

The Security Systems Development Life Cycle (SecSDLC) The same phases which is used in traditional SDLC can be adapted to support specialized implementation of IS project,At its

Describe the time limit problem, Problem: (a) Use a simple example to ...

Problem: (a) Use a simple example to explain what is meant by a finite state machine. (b) Describe the time limit problem in an interrupt-driven system. (c) A certain m

Attackers motives behind the cyber attack, Attacker's Motives behind the Cy...

Attacker's Motives behind the Cyber Attack Before adapting the necessary measures to deal with the problem, understanding and evaluating the blogger's psyche and his motivation

Why use an ids, WHY USE AN IDS? IDS prevent from problem behaviors by in...

WHY USE AN IDS? IDS prevent from problem behaviors by increasing the perceived risk of discovery and punishment. Detect the attacks and other security violations. Detect and at

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