Describe how bob can recover the message

Assignment Help Computer Network Security
Reference no: EM13657173

Question 1: Alice and bob agree to communicate privately via e-mail using a scheme based on RC4 but they want to avoid using a new secret key for each transmission. Alice and bob privately agree on 128-bit key k. To encrypt a message m consisting of a string of bits, the following procedure is used.

1. Choose a random 80- bit value v

2. Generate the ciphertext c = RC4(v||k)⊕m

3. Send the bit string(v||c)
a. Suppose Alice uses this procedure to send a message m to Bob. Describe how Bob can recover the message m from (v ll c) using k.
b. If an adversary observes several values (V1 ||C1), (V2, C2).......transmitted be-tween Alice and Bob. how can he or she determine when the same key stream has been used to encrypt two messages?

Question 2:  With the ECB mode. if there is an error in a block of the transmitted ciphertext, only the corresponding plaintext block is affected. However, in the CBC mode, this error propagates. For example. an error in the transmitted C1 (Figure 2.9) obviously cor¬rupts P1 and P2.

a. Are any blocks beyond P2 affected?

b. Suppose that there is a bit error in the source version of P1. Through how many ciphertext blocks is this error propagated? What is the effect at the receiver?

Reference no: EM13657173

Questions Cloud

Profit assembly paint inspection : Profit Assembly Paint Inspection
What is his annual inventory turns : What is his annual inventory turns?
What lens must be used to see clearly an object at infinity : The near point of a certain eye is 100 cm in front of the eye. What lens must be used to see clearly an object 25 cm in front of the eye? The far point of a certain eye is 1 m in front of the eye. What lens must be used to see clearly an object at in..
Minimize the advertising budget : Minimize the advertising budget.
Describe how bob can recover the message : Describe how Bob can recover the message - Through how many ciphertext blocks is this error propagated? What is the effect at the receiver?
The limits of the visible spectrum : The limits of the visible spectrum are about 400 nm to 700 nm. Find the angular breadth of the first order visible spectrum produced by a plane grating having 15,000 lines per inch, when light is incident generally on the grating.(1inch = 2.54 cm)
Decide the angular speed of the wheel : An automobile tire has a radius of 0.380 m, and its center moves forward with a linear speed of v = 18.0 m/s. Decide the angular speed of the wheel.(Assume that there is no slipping of the surfaces in contact during the rolling motion.)
What are some major capacity issues in a hospital? : What are some major capacity issues in a hospital?
What is the ratio of potential energy to kinetic energy : What is the ratio of potential energy to kinetic energy for a comet that has now enough energy to escape from the Sun's gravitational field?

Reviews

Write a Review

 

Computer Network Security Questions & Answers

  Network security

Network Security

  Security by obscurity

Defacement, Infiltration, Phishing, Pharming, Insider Threats, Click Fraud, Denial of Service, Data Theft/Loss, IP Whitelisting and IP Spoofing, recursive PHP functio, worm and a virus, hash on a string using MD5

  Prepare a graph of the storage requirements

Prepare a graph of the storage requirements for the project.

  A firewall works by blocking incoming

A firewall works by blocking incoming requests. Explain how a firewall can distinguish between two incoming requests allowing one while denying the other??

  Cybersecurity research paper

Identifying and explaining how the breach occurred and identifying and discussing known or suspected losses of confidentiality, integrity, and availability for information and/or information systems

  Describe the integrative functions

Describe the various integrative functions and processes within the information systems area, including databases, systems analysis, security, networking, computer infrastructure, human computer interaction, and Web design.

  Create list of security issues which the firm must monitor

You decide to create security checklist for New Century. Create list of security issues which the firm must evaluate and monitor. Make sure to organize items into categories which match five security levels.

  Appraise the individual and organizational consequences of

1.compare and contrast the mis in place in two distinctly different organizations.2.compare each organizations use of

  Determine public values transmitted for message

Alice and Bob select the numbers 6 and 10 privately. What will be public values they transmit and what would be final secret computed?

  The discussion board is part of the core of online

the discussion board is part of the core of online learning. classroom discussion in an online environment requires

  In your own words how would you describe the dhcp

in this assignmentnbspyou will use thenbspcourse materials and the web tonbspresearch host ip addressing conflicts

  Write a succinct policy statement specifying employee

Summarize the primary vulnerabilities and potential threats that exist for GCI related to the practice of storing sensitive data on laptops. In your opinion, which of the risks GCI faces are most significant to the company?

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