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

Lan topologies, Network can be distinguished by shape. According to which t...

Network can be distinguished by shape. According to which there are three most popular methodologies, which are shown as follows; Star Ring Bus

Firewall analysis tools-information security, FIREWALL ANALYSIS TOOLS Th...

FIREWALL ANALYSIS TOOLS There are a number of tools automate remote discovery of firewall rules and assist the administrator in analyzing rules Administrators who feel wary of u

Elements of cryptosystems-cryptography, Elements of Cryptosystems Crypto...

Elements of Cryptosystems Cryptosystems is characteristically made up of algorithms, data handling techniques, and procedures which are combined in multiple ways to ensure confi

Assignment, for making the assignment

for making the assignment

Explain how ethernet deals with collisions, (a) Describe how CSMA/CD operat...

(a) Describe how CSMA/CD operates and explain how Ethernet deals with collisions. (b) Describe how the subsequent protocols work: i. ARP ii. DHCP iii. DNS iv. SMTP (c) The

Non-repudiation and auditing, Proof that the sender forwards the message. I...

Proof that the sender forwards the message. It also prohibits the author of the code from falsely denying that he forward the message. This is achieved by record using the exact ti

Access controls-information security, Access Controls Access controls ad...

Access Controls Access controls addresses admission of a user into a trusted area of organization. It comprises of a combination of policies & technologies. The ways to control

Draw the full network diagram, Problem (a) Below is a capture of an E...

Problem (a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. The second screen capture is from the data portion of the frame.

Briefly explain the following security goals, (a) Briefly explain the fo...

(a) Briefly explain the following security goals provided by cryptography: confidentiality, authentication, integrity and non-repudiation. (b) State Kerckhoff's Princip

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