(a)

(i) Bob has public RSA key (n = 77, e = 7).

Show that Bob's private key is (d = 43).

(ii) Alice wants to send the message m = 13 to Bob. She encrypts the message using Bob's public key. What is the value of the ciphertext that Alice sends to Bob?

(iii) David has also sent an encrypted message to Bob. The ciphertext value that Bob receives from David is 17. Showing all your working, use Bob's key to decrypt this ciphertext and recover the value of David's message.

(b)

Consider cryptographic hash functions.

(i) What is meant by collision resistance for a hash function?

(ii) What common usage do hash functions have in connection with digital signatures?

(iii) What is the difference between a hash function and a message authentication code (MAC)?

(iv) Why is it recommended to use a hash function with 2n bits of output when it is used as component in a system designed for n bits of security?

Posted Date: 10/22/2013 2:52:00 AM | Location : United States

Ask an Expert

Related Discussions:- Cryptographic hash functions, Assignment Help, Ask Question on Cryptographic hash functions, Get Answer, Expert's Help, Cryptographic hash functions Discussions

Write discussion on Cryptographic hash functions
Your posts are moderated

Write your message here..

Related Questions

People, People,Procedures,Data Asset Identification-Risk Management Th... People,Procedures,Data Asset Identification-Risk Management The human resources, data information and documentation assets are more difficult to identify. People having knowle

Introduction to planning for security, INTRODUCTION TO PLANNING FOR SECURIT... INTRODUCTION TO PLANNING FOR SECURITY The creation of an information security program begins with creation and review of organization’s information security policies, standards,

Wan architecture and wan service, MegaCorp INC. is a large manufacturing f... MegaCorp INC. is a large manufacturing firm that operates 5 factories in Dallas, 4  factories in Los Angeles, and 5 factories in Albany, New York.  It operates a tightly  connected

Basic functions of e-mail system, B a s i c functions of e-mail system ... B a s i c functions of e-mail system are given as follows: C o mp o sition refers to the procedure of creating messages and the answers. Though any text editor can be

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

Analysis phase in the building-block approach, QUESTION: a) Explain fou... QUESTION: a) Explain four issues that are generally addressed in the Needs Analysis phase in the building-block approach to network design. b) Sketch a typical hybrid star-b

Packets and frames, PACKETS: Packet is a generic word that define to sma... PACKETS: Packet is a generic word that define to small code of data. Packet have different format. Each hardware needs different packet format.  FRAME: A hardware frame or

Tcp- reliable transport service, TCP-RELIABLE TRANSPORT SERVICE INTRO... TCP-RELIABLE TRANSPORT SERVICE INTRODUCTION:  TCP is the major transport protocol architecture in the TCP/IP suite. It uses unreliable datagram function offered by IP whe

Tracing a route, There is another probing methods i-e Trace Route. To get m... There is another probing methods i-e Trace Route. To get more detail it is used     As given in the figure about the route to DANDELION-PATCH.MIT.EDU was looked out a

How to check Network working , How to check Network working How to check Network working