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

Evaluations, Evaluations, Assessment, and Maintenance of Risk Controls W...

Evaluations, Assessment, and Maintenance of Risk Controls When the control strategy has been implemented, it should be monitored and measured on an ongoing basis to determine ef

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

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Explain the schemes for distribution of public keys, (a) What is a pseudora...

(a) What is a pseudorandom generator? Give an example describing how it works. (b) Explain the key components of a wireless network and their purpose. (c) Describe the authen

Network management, Ask question #MinimAn NMS is connected to a remote netw...

Ask question #MinimAn NMS is connected to a remote network by a 64 Kb/s link. The network elements in the remote network generate 50 faults/second. Of these, 5% are critical and th

How will network datagrams be protected at network layer, (a) Consider the...

(a) Consider the subsequent authentication options: A. Using password. B. Using pin and fingerprint Which option A or B provides stronger security and why? (b) Give

Security goals, what is relation ship between computer security goals?

what is relation ship between computer security goals?

Describe the time limit problem, Problem: (a) Use a simple example to ...

Problem: (a) Use a simple example to explain what is meant by a finite state machine. (b) Describe the time limit problem in an interrupt-driven system. (c) A certain m

Nessus vulnerability, You see two IP addresses. The IP address 192.168.58.1...

You see two IP addresses. The IP address 192.168.58.130 is the one of Bt4. The IP address 192.168.58.133 has ports 135 and 445 open; which indicates that it is a Windows machine. S

Define bridges, Bridges perform both in the data link layers and physical...

Bridges perform both in the data link layers and physical of LANs of same kind. They split a bigger network in to smaller segments. They have logic that accept them to store 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