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

Websphere administrator, Websphere Administrator: Working as Webspher...

Websphere Administrator: Working as Websphere Administrator in the department called DART (Database Architecture Re-Engineering and Tuning). The major responsibilities are t

Benchmarking-information security, Benchmarking An alternative approach to...

Benchmarking An alternative approach to risk management is Benchmarking. It is process of seeking out and studying practices in other organizations which one’s own organization de

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

What is mac address, MAC Address The address for a machine as it is id...

MAC Address The address for a machine as it is identified at the Media Access Control (MAC) layer in the network structure. MAC address is generally stored in ROM on the n

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

Security and basics steps in writing thesis, how can i start thesis? Please...

how can i start thesis? Please mention so of examples?

Routing protocol for a banking network, You have been asked to design a Ban...

You have been asked to design a Banking Network with two primary types of locations.  Branches that will have 3 subnets, one /25 subnet one /26 subnet for ABMS and one /26 s

Internet protocol (ipv6), SUCCESS OF IP:  IP has accommodated dramatic...

SUCCESS OF IP:  IP has accommodated dramatic modification since real design. But basic rules are still appropriate today. There are many new kinds of hardware. SCALING:

Computer security, Assume that the RSA problem is hard, prove that the RSA ...

Assume that the RSA problem is hard, prove that the RSA encryption is secure against IND- CPA. Provide a game between an adversary A and a simulator (or challenger) B.

Use the chinese remainder theorem to evaluate x, Use the Chinese remainder ...

Use the Chinese remainder theorem to evaluate x from the following simultaneous congruences: x ≡ 1 (mod 2); x ≡ 2 (mod 3); x ≡ 3 (mod 5). Calculate gcd(14526, 2568). (

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