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

Provide the network configuration, QUESTION: a) Below is a capture of a...

QUESTION: a) Below is a capture of an Ethernet II frame which has an IPv4 packet and a segment. Provide the source MAC address in hexadecimal; the source IP address, the length

Efforts of advanced research project agency, ADVANCED RESEARCH PROJECT AGEN...

ADVANCED RESEARCH PROJECT AGENCY (ARPA) The efforts of ARPA was to active all its research groups have accept to new era computers. For this purpose ARPA started investing in wa

Secure clustering in WSNs, i have an idea of clustering in wsns . where eac...

i have an idea of clustering in wsns . where each and every sensor node use the reputation scheme and while clustering provide help against the selfishness atatck of the sensor nod

Access control list, Scenario: A network with individual hosts (really, vir...

Scenario: A network with individual hosts (really, virtual machines) can run HTTP (web) servers that are available to the outside. (Here, available means the ability to read and wr

Collision, COLLISION: The receiver can get simultaneous requests, which gi...

COLLISION: The receiver can get simultaneous requests, which gives in collision at receivers and both service lost and in this way no transmitter accepts reservations and both use

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

Bus topology, In BUS topology every computer is directly connected to p...

In BUS topology every computer is directly connected to primary network cable in a single way. Bus networks are the easiest way to connect multiple users, but can have problems

Intrusion detection and classification, i want to detec and classify networ...

i want to detec and classify network anomaly detection based on KDD99 data set using swarm intelligence

Attacks on wireless network, Q. Attacks on wireless network WSN are vul...

Q. Attacks on wireless network WSN are vulnerable to attacks which compromise the integrity of the WSN nodes by decreasing the nodes' fault tolerance capabilities, data distrib

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