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

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

Describe the process of components identification, Probelm 1: Give the ...

Probelm 1: Give the History and Evolution of Wireless Communication System. Complete explanation Probelm 2: Describe the process of Components Identification and cal

Improving domain blacklisting - spam mail, Improving domain blacklisting: ...

Improving domain blacklisting: Current domain blacklisting techniques are not very effective as spammers keep replacing blacklisted domains with newly registered domains. Also

Ip datagram, IP DATAGRAM Various options can be included to IP header,...

IP DATAGRAM Various options can be included to IP header, e.g., source route, record route and timestamp. Header with no function has H. LEN field value 5; data starts immedia

Describe benefits of effective communication, Question: (a) Explain the...

Question: (a) Explain the following terms: Information Communication Technology, Operating System and Application Software. (b) Define what a computer is, give four anatomi

Locality of reference , LOCALITY OF REFERENCE PRINCIPLE:  Principle of...

LOCALITY OF REFERENCE PRINCIPLE:  Principle of "Locality of Reference" use to predict computer interaction patterns. There are two patterns shown as follows: a) Spatial loca

Collision detection, COLLISION DETECTION The signals from two devices ...

COLLISION DETECTION The signals from two devices will interfere with each other and the overlapping of frames is known a collision. It does not cause to the hardware but data

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

Bus topology, BUS TOPOLOGY In a bus topology all devices are attached ...

BUS TOPOLOGY In a bus topology all devices are attached to a single long cable and any device can send data to any other device. For this function, coordination is needed to d

Parsing ipv6 headers, PARSING IPv6 HEADERS Base header is fixed in siz...

PARSING IPv6 HEADERS Base header is fixed in size i.e. 40 octets. NEXT HEADER field in the base header describe kind of header and it seems at end of fixed-size base header. S

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