Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Computer Network & Security Expert

problem 1: problems for short answers

1) Suppose that f: {0, 1}n → Zp where p is a large prime and n > p. Prove that f(x) = gx

(mod p) is not second pre-image resistant, where g is a generator of Zp. What is the security assumption you use, if to make it pre-image resistant.

2) Show that the active CCA against ElGamal encryption given in the lecture does not work when against the Cramer-Shoup encryption.

3) Show that the RSA encryption is insecure against a chosen ciphertext attack. In particular, given a ciphertext y, describe how to choose a ciphertext y' such that knowledge of the plaintext x' = DK(y') allows the attacker to determine x = DK(y).

4) Show that the RSA encryption is not semantically secure. Provide a game between an adversary A and a simulator (or challenger) B.

5) Let p = 151. Choose a generator for GF(143)*. Choose an appropriate private and ephemeral key. Perform the following on the message m = 113, or the next appropriate message:

(a) Encrypt m using ElGamal.
(b) Signing m using ElGamal.

You can use Pari/GP.

6) Assume an elliptic curve with points whose coordinates P = (x; y) satisfy the following congruence y2 = x3 + x mod 23. Given two points P = (1; 5) and Q = (9; 5), what are the points P + Q, P + P, and Q + Q?

7) Show that if the Gap Die-Hellman Problem is easy, then the Cha-Cheon signature scheme will be broken.

8) Show that the Cha-Cheon signature scheme will be broken if the Gap Die-Hellman Problem is solved in a signature forgery reduction by forking. Do not need to give a formal proof.

9) Describe the Bilinear Die-Hellman (BDH) Problem and describe why the Boneh-Franklin identity-based encryption scheme is broken if the BDH problem is easy. Is the Basic version of Boneh-Franklin identity-based encryption scheme CCA secure? Why?

problem 2: Design a communication protocol based on identity-based cryptography

Alice and Bob are located at di erent locations and want to communicate securely by the computer network. Their identities are public. They are equipped with the Bone-Franklin ID-based encryption scheme, the Cha-Cheon signature scheme and AES, which should be properly used in their communication protocol. Your protocol must meet the following requirements:

A) Key generation: They need to generate their keys. Describe it in detail. Include all parties who have to be involved in key generation.

B) Mutual Authentication: They should know the origin of a message, i.e., who sent the message.

C) Con dentiality: Messages must be protected and should not be disclosed to others.

D) Session Key Establishment: Alice and Bob need a symmetric session for each of their communication session.

Your protocol should have three steps:


Step 1: Alice sends a message to Bob.

Upon receiving this message, Bob is convinced that the message comes from Alice and no one else apart from Alice has seen the message.


Step 2: Bob responds:

Upon receiving the response, Alice is convinced that Bob has received her previous message and has read the content. She is also sure that Bob's response must come from Bob and no one else apart from Bob has seen it.


Step 3: They communicate each other with a symmetric session key, which was established in Steps 1 and 2. Provide detailed protocol steps.

The protocol will be assessed in terms of these requirements. Describe how these requirements are met in your protocol. You must provide the algorithms (math) in your protocol.

Computer Network & Security, Computer Science

  • Category:- Computer Network & Security
  • Reference No.:- M91884

Have any Question? 


Related Questions in Computer Network & Security

Lab assignment- assessment questions1 explain the two

Lab Assignment- Assessment Questions 1. Explain the two different types of attacks that can be performed in Cain and Abel to crack user account passwords. Which do you think is the most effective and why? 2. Compare and ...

Network simulation projectsimulation projectobjectivesbull

Network Simulation Project Simulation Project Objectives • Design and analyze the performance of a network under different traffic conditions. • Design and analyze the performance of a wide area network. • Investigates t ...

Project infrastructure and securitythis assignment consists

Project: Infrastructure and Security This assignment consists of two sections: an infrastructure document and a revised Gantt chart or project plan. You must submit both sections as separate files for the completion of t ...

Proposal projectchoose one of the following for this

Proposal Project Choose one of the following for this project and See attachment for complete instruction and please remember to send a turnitin report. 1) Metasploit 2) Wireshark 3) Back Track 4) Nessus 5) Cain & Abel P ...

Network management paperin this paper you will research and

Network Management Paper In this paper, you will research and report on network management tools associated with (1) policy compliance, (2) bandwidth management, and (3) asset management. Compare and contrast, at least, ...

Q1 the first transcontinental telephone service was

Q1. The first transcontinental telephone service was established in the 1940s. a. true b. false Q2. The Internet was started by the U.S. Department of defense in 1969 as a network of four computers called ARPANET. a. tru ...

Assignment designing compliance within the lan-to-wan

Assignment: Designing Compliance within the LAN-to-WAN Domain Imagine you are an Information Systems Security Officer for a medium-sized financial services firm that has operations in four (4) states (Virginia, Florida, ...

You work the night shift at a software development company

You work the night shift at a software development company and mange six Web servers that host the company's e commerce solution for medical and dental supplies. You notice that traffic across the network dropped signifi ...

What is a dmz is this really a good name for the function

What is a DMZ? Is this really a good name for the function that this type of subnet performs? What is RADIUS? What advantage does it have over TACACS? How does a network-based IDPS differ from a host-based IDPS? What is ...

Discussiontroubleshooting please respond to the followingas

DISCUSSION Troubleshooting" Please respond to the following: ?As explained throughout the text, troubleshooting is a structured methodology that requires personal fine-tuning. With that in mind, suppose a user at your co ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro