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

Packets and frames, PACKETS: Packet is a generic word that define to sma...

PACKETS: Packet is a generic word that define to small code of data. Packet have different format. Each hardware needs different packet format.  FRAME: A hardware frame or

Distinguish between passive and active attacks, Problem (a) Distinguis...

Problem (a) Distinguish between passive and active attacks. (b) Give two reasons why it is important to organise security awareness programs for users. (c) Describe how

Imap and pop functions, How does the POP functions? What are the advantages...

How does the POP functions? What are the advantages/benefits of IMAP over POP? POP stands for Post Office Protocol, version 3 (POP3) is one of the easiest message access protoc

Hardware trojan detection, how to form the trojan integrated cirucit and wh...

how to form the trojan integrated cirucit and what are the tools are used to simulate the ciruit to our system and how to pass it as input to the clustering algorithm to get the ou

Pseudonymous remailers and cypherpunk remailers, Problem (a) As a fore...

Problem (a) As a forensic investigator, you are needed to trace the source of an email. It is suspected that the email header has been forged. Show how you would proceed to

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.

Ipv6 base header format, IPV6 BASE HEADER FORMAT: It has less informat...

IPV6 BASE HEADER FORMAT: It has less information than IPV4 message header. Next header shows to first extension message header. Flow label is partitioned into a TRAFFIC CLASS

Describe how lower bounds on arc flows, QUESTION: (a) Suppose the graph ...

QUESTION: (a) Suppose the graph below, use the Flow Decomposition method to list the cycles and paths produced. (b) Describe how Lower Bounds on Arc Flows are eliminated

What do you understand by the concept web of trust, Question: a) Name ...

Question: a) Name a method to allow a person to send a confidential email to another person, without risks of a third-party reading the email. Describe briefly the operations

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

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