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

Processing an incoming arp message, PROCESSING AN INCOMING ARP MESSAGE ...

PROCESSING AN INCOMING ARP MESSAGE When an ARP message reaches, the protocol specifies that the receiver must operate two basic steps. First the receiver finds the sender's add

Logic bombs - attacks information security, Example 3: Logic bombs In th...

Example 3: Logic bombs In the year 2000, Timothy Lloyd was found responsible of causing $10 million and $12 million of damage to Omega Engineering, an American company specializ

Ids response behavior, IDS RESPONSE BEHAVIOR Once IDS detects an anomalo...

IDS RESPONSE BEHAVIOR Once IDS detects an anomalous network situation, it has a number of options. IDS responses to external stimulation can be classified as active or passive.

Address resolution with table lookup, ADDRESS RESOLUTION WITH TABLE LOOKUP ...

ADDRESS RESOLUTION WITH TABLE LOOKUP : Resolution needs data structure that has information about address binding. A distinct address-binding table is used for every physical n

Distinguish between a mobile agent state and code, Question: (a) Disti...

Question: (a) Distinguish between a mobile agent "state" and "code". (b) Differentiate between "weak" and "strong" mobility. (c) Mobile agent systems are known to have

Why is this setup not secure, Question: a) You are using Active Directo...

Question: a) You are using Active Directory Users under Windows Server 2003 and Computers to configure user objects in your domain, and you are able to change the address and

TCP/IP v OSI, What are the main differences between TCP/IP vs OSI?

What are the main differences between TCP/IP vs OSI?

Http protocol, Question (a) Name 3 popular electronic mail access prot...

Question (a) Name 3 popular electronic mail access protocols? (b) i. What is DNS? ii. Briefly, describe what it does and how it works? iii. Why does DNS use a dist

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

Draw the network layout, Question : a) Below is a capture of an Etherne...

Question : a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. Give the source MAC address for the frame in hexadecimal; the source I

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