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

Wireless security tools, WIRELESS SECURITY TOOLS An organization which s...

WIRELESS SECURITY TOOLS An organization which spends its time securing wired network and leaves wireless networks to operate in any manner is opening itself up for security brea

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

Calculate euler totient function value, (a) Explain the importance of the ...

(a) Explain the importance of the Euler Totient function in Cryptography. Calculate Euler Totient function value, φ(1280). (b) Explain the role of the Authentication Server (

Ip datagram header format, IP DATAGRAM HEADER FORMAT:  It is given in...

IP DATAGRAM HEADER FORMAT:  It is given in the figure below:   In the table: VERS denotes the version of IP. H.LEN denotes the header length in units of

The Security Systems Development Life Cycle (SecSDLCtle.., #Under what circ...

#Under what circumstances would the use of a SecSDLC be more appropriate than an SDLC?

Star topology, In Star topology all computers are connected using a cen...

In Star topology all computers are connected using a central device known as hub. Star networks are one of the most general computer network topologies. In its simplest way, a

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

Man-in-the-middle attacker, - Alice, Bob and Charlie have a secret key a=3,...

- Alice, Bob and Charlie have a secret key a=3, b=4, c=5, in that order. - They would like to find a common secret key using Diffie-Hellan key exchange protocol (with g=2, p=5).

Describe the role of dns root servers in network, QUESTION (a) Describ...

QUESTION (a) Describe the role of DNS root servers in the Internet network. (b) What do you understand by the handover concept in a mobile network? (c) List five meth

Explain major differences between wpa and wpa2, Question: Suppose the f...

Question: Suppose the following brief history of WLAN security standards: When the security of WEP was broken, the industry turned to the IEEE to fix it. The IEEE said it could

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