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

Develop a completely secure wsn based on the triple key, Q. Develop a compl...

Q. Develop a completely secure WSN based on the triple key? Wireless network is the most vulnerable type of network to security attack. Unauthorized access to wireless network

Udp datagram format, UDP DATAGRAM FORMAT: It is given in the figure be...

UDP DATAGRAM FORMAT: It is given in the figure below:

Systems-specific policy (syssp), Systems-Specific Policy (SysSP) SysSP...

Systems-Specific Policy (SysSP) SysSPs are codified as standards and procedures which are used when configuring or maintaining systems. Systems specific policies fall into 2 g

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

Example bus network , Ethernet is a commonly used LAN technology. It was di...

Ethernet is a commonly used LAN technology. It was discovered at EXROX PARC(Palo Alto Research Center) in 1970s.Xerox, Intel and Digital described it in a standard so it is also kn

Access control devices-cryptography, ACCESS CONTROL DEVICES Successful a...

ACCESS CONTROL DEVICES Successful access control system includes number of components, which depends on system’s requirements for authentication and authorization. Powerful auth

Audit or review of the information security issues, Using the selected appr...

Using the selected approach, you should then conduct an audit or review of the information security issues associated with the use of computing facility and report on the findings.

Programming, SDES encryption and decryption

SDES encryption and decryption

Extended euclidean algorithm, (a) Using the extended Euclidean algorithm, ...

(a) Using the extended Euclidean algorithm, find the multiplicative inverse of 504 mod 67. (b) Decrypt the following ciphertext, which has been encrypted using Caesar cipher:

Arrangement of self-learning switches, QUESTION a) Consider the speed ...

QUESTION a) Consider the speed of propagation of an electrical signal is same to 2x10 8 m/s, evaluate the ratio of the propagation delay to the transmit time for the given typ

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