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

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

What is information security, What is information security Information s...

What is information security Information security protects information (and facilities and systems which store, use and transmit it) from a broad range of threats, in order to p

Evaluate the sample correlation between y and z, Question: (a) Data on ...

Question: (a) Data on four variables are stored in a file called file1.dat. The first line of the file is the variable names f, x, y and z. Give the R commands to (i) read t

Research paper, how much would you charge for minimum 20 pages

how much would you charge for minimum 20 pages

Social network development in java , Social Network development in Java: ...

Social Network development in Java: Project Title: SUGGESTLOCAL (Nov 2006-April 2007) Role             : Developer Domain        : Social Network Client          :

Tomcat server, how to access tomcat by internet

how to access tomcat by internet

Explain the basic network topologies, Question: (i) ‘Implementation' is...

Question: (i) ‘Implementation' is a critical stage of the Systems Development Life Cycle. Show the four approaches which are commonly used to implement information systems in

Limitations of ethical dilemma, The best results obtained in the PIIT class...

The best results obtained in the PIIT classes have been when the technique has been used in tutorial groups, rather than have students submit individual reflections on particular c

Encryption key size-cryptography, Encryption Key Size When using ciphers...

Encryption Key Size When using ciphers, the size of crypto variable or key is quite important as the strength of many encryption applications and cryptosystems were measured by

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