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

Characteristics of radial basis function neural networks, Problem : (a)...

Problem : (a) Provide one possible classification of PCA, ART, RBF, and Fuzzy ARTMAP networks. (b) Describe in detail the characteristics of Radial Basis Function Neural Net

Describe the two possible configurations for 3des, QUESTION (a) Describ...

QUESTION (a) Describe the two possible configurations for 3DES (b) What is the main disadvantage of 3DES? (c) Why are most modern symmetric algorithm block ciphers? (d

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

Increasingly significant impact on society, Question: (a) African gove...

Question: (a) African governments are slowly shifting to more transparent ICT regulations. However, but limited spectrum availability remains a key barrier to sustaining lon

Sequential label and supply, What questions should Iris ask Charlie about t...

What questions should Iris ask Charlie about the new job, about Kelvin''s team, and about the future of the company?

Programming, For this assignment you will create a program called MMWordFix...

For this assignment you will create a program called MMWordFix (Multi-Mode WordFix). This program prompts the user to select one of three word filters (uppercase, lowercase, encryp

Innovative nature of triple key management, Innovative nature of triple key...

Innovative nature of triple key management The triple key management scheme provides secure services by combining different techniques whic contribute to the security and priv

Extended euclidean algorithm, (a) Using the extended Euclidean algorithm, ...

(a) Using the extended Euclidean algorithm, find the multiplicative inverse of 504 mod 67. (b) Decrypt the following ciphertext, which has been encrypted using Caesar cipher:

Project, Network diagram for a mediacal care

Network diagram for a mediacal care

Categories of controls-information security, Categories of Controls Cont...

Categories of Controls Controlling risk through mitigation, avoidance or transference is accomplished by implementing controls. There are 4 effective approaches to select the co

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