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

Assignmentyou have been asked by a local charity retail

Assignment You have been asked by a local charity retail organization to install a network in its downtown office. It currently has seven PCs running Windows XP Home Edition. They are configured as follows: Pentium 4 at ...

Technical paper project disseminating organizational it

Technical Paper Project: Disseminating Organizational IT Security and Troubleshooting Best Practices Part 1 Write a ten to fifteen page paper in which you analyze and solve the following issues: Imagine you are a senior ...

Or the purpose of the first part of this project you are

Or the purpose of the first part of this Project, you are still the InfoSec Specialist for the Greenwood Company. Consider this project a continuation of the work you performed in Projects 1 and 2. After seeing you searc ...

1 when an organization undertakes an infosec-driven review

1. When an organization undertakes an InfoSec-driven review of job descriptions, which job descriptions must be reviewed? Which IT jobs not directly associated with information security should be reviewed? 2. List and de ...

Assignmentyour boss has had an intrusion or so she says on

Assignment Your boss has had an intrusion (or so she says) on his home network. She has brought in a packet capture file for you to analyze. She says: "Something has happened on my home network. I use my network for inte ...

Assignment case study handmade furniture ltdthis case study

Assignment case study: HandMade Furniture Ltd. This case study provides background information for both assignment 1 and assignment 2. As a network consultant, your initial examination of the company has discovered the f ...

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 ...

Case study cyber security in business Case Study: Cyber Security in Business

Case Study: Cyber Security in Business Organizations Protecting organizational assets and information within the company has become a top priority for many organizational leaders. Review the article titled "Missed Alarms ...

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 ...

Q1 the rijndael algorithm was chosen for the advanced

Q1: The Rijndael algorithm was chosen for the Advanced Encryption Standard (AES). Using either the attached tutorial, or your own sources of information, pick one (or more) steps of the algorithm and explain it in some d ...

  • 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

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

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen