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

Address resolution , Mapping between a hardware address and a protocol addr...

Mapping between a hardware address and a protocol address is known Address Resolution. A router or host uses address resolution when it requires to transmit a packet to another dev

Wfabilling project in java, WFABilling project in Java:  Project Title...

WFABilling project in Java:  Project Title: WFABilling   Role                      : Developer Domain                 : Tele-Com Environment          : Java, J2EE, S

[email protected], Re: Website Google Ranking Hello! Hope yo...

Re: Website Google Ranking Hello! Hope you are doing well. I discovered some major issues in your website which might be the cause for the Google Penalties and poor search ranki

Define secure socket layer (ssl), Secure Socket Layer (SSL) accepts a combi...

Secure Socket Layer (SSL) accepts a combination of asymmetric and symmetric (public-key) encryption to accomplish integrity, confidentiality, authentication and non-repudiation for

Routing table, ROUTING TABLE For efficiency, information about forward...

ROUTING TABLE For efficiency, information about forwarding is saved in a routing table, which is started at system initialization and must be updated as network topology modif

Explain the main stages in the penetration testing process, Question: (...

Question: (a) i. Explain what is meant by Discretionary Access Control and Mandatory Access Control ii. Which method would be the most effective to ensure that users do

What are the intermediate systems and how they work, Question: a) Expla...

Question: a) Explain what the following intermediate systems are and how they work? i. Repeater ii. Bridge b) A service is formally specified by a set of primitives (op

Tomcat server, how to access tomcat by internet

how to access tomcat by internet

Placeholders for the plaintext characters, Encode the following plaintext, ...

Encode the following plaintext, using the Caesar cipher:             LORD OF THE RINGS b) The following ciphertext              jw njbh lxmn cx kanjt has been encoded usi

Understanding a business model of a spammer, The first and foremost need of...

The first and foremost need of  any business is a role to perform for its client base, and for the spammer this will typically be the role of advertising products which, due to the

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