Purchase Solution

Network crashes

Not what you're looking for?

Ask Custom Question

1.Suppose we are using Lamport's hash, and Bob's system crashes before receiving Alice's reply to a message. Further suppose an intruder, Trudy, can eavesdrop and detect that Bob crashed (maybe Trudy can even cause Bob to crash). This would create a situation where Trudy has Alice's reply (which Bob did not receive) and which Trudy can use to impersonate Alice, assuming Trudy logs in before Alice attempts to log into Bob again. How can we modify Bob's behaviour to prevent this threat, and exactly when would we overwrite Bob's database, and with what?

Purchase this Solution

Solution Summary

Network crashes are hypothesized.

Solution Preview

Lamport's hash implements a one-time password protecting against eavesdropping and password file theft.
The server stores for each user
1. the user name,
2. an integer n,
3. the n-fold hash of the password: hashn(password).
If the user wants to log on, the user types in the password. Her machine sends a request to the server, which answers with a prompt for n. The user's machine calculates hashn-1(password) and sends this to the server. The server calculates hash(hashn-1(password)) = hashn(password). If this value matches the one ...

Purchase this Solution


Free BrainMass Quizzes
Word 2010: Table of Contents

Ever wondered where a Table of Contents in a Word document comes from? Maybe you need a refresher on the topic? This quiz will remind you of the keywords and options used when working with a T.O.C. in Word 2010.

C# variables and classes

This quiz contains questions about C# classes and variables.

Inserting and deleting in a linked list

This quiz tests your understanding of how to insert and delete elements in a linked list. Understanding of the use of linked lists, and the related performance aspects, is an important fundamental skill of computer science data structures.

Basic Networking Questions

This quiz consists of some basic networking questions.

Javscript Basics

Quiz on basics of javascript programming language.