THE WHATIS.COM WORD-OF-THE-DAY December 31, 2002 chaffing and winnowing ______________ TODAY'S SPONSOR: VeriSign - The Value of Trust
Secure all your Web servers now - with a proven 5-part strategy. The FREE Server Security Guide shows you how to: - DEPLOY THE LATEST ENCRYPTION and authentication techniques - DELIVER TRANSPARENT PROTECTION with the strongest security without disrupting users. And more. Get your FREE Guide now: http://WhatIs.com/r/0,,8717,00.htm?freeguide ______________ TODAY'S WORD: chaffing and winnowing See our complete definition with hyperlinks at http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci786707,00.html Chaffing and winnowing are dual components of a privacy-enhancement scheme that does not require encryption. The technique consists of adding false packets to a message at the source (sender end of the circuit), and then removing the false packets at the destination (receiver end). The false packets obscure the intended message and render the transmission unintelligible to anyone except authorized recipients. At the source, each legitimate message packet is assigned a unique serial number and a message authentication code (MAC). Every serial number and MAC is known to the receiver in advance. Then the bogus packets are added at the source; this is the chaffing process (chaff is the undesirable part of a plant such as wheat that is separated during milling). The chaff packets have the same format as the legitimate ones, and they also have reasonable serial numbers, but they have invalid MACs. It is impossible to tell the difference between the legitimate packets and the chaff except by comparing MACs at the destination. At the destination, the chaff packets are removed by comparing MACs. This is called winnowing. If an incoming packet has a bogus MAC, it is discarded; if it has a legitimate MAC, it is accepted. Thus, the original message is recovered. RELATED TERMS: encryption http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci212062,00.html packet http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci212736,00.html ______________________ SELECTED LINKS: The MIT Lab Computer Science offers a white paper. http://theory.lcs.mit.edu/~rivest/chaffing.txt SearchSecurity.com offers tips for enhancing the privacy of data. http://searchsecurity.techtarget.com/bestWebLinks/0,289521,sid14_tax281916,00.html ______________________ WHATIS.COM POLL | IT Training How many times this year did your company send you for IT training? >> Cast your vote in our latest member poll http://whatis.techtarget.com/poll/1,289525,sid9,00.html ______________________________ RECENT ADDITIONS AND UPDATES [1] Online Service System http://searchsap.techtarget.com/sDefinition/0,,sid21_gci871202,00.html [2] CATT http://searchsap.techtarget.com/sDefinition/0,,sid21_gci871110,00.html [3] R/3 Repository http://searchsap.techtarget.com/sDefinition/0,,sid21_gci871109,00.html [4] user exit http://searchsap.techtarget.com/sDefinition/0,,sid21_gci871107,00.html [5] race condition http://searchstorage.techtarget.com/sDefinition/0,,sid5_gci871100,00.html ____________________________________________________________________ ::::::::::::::::::: WHATIS.COM CONTACTS ::::::::::::::::::: LOWELL THING, Site Editor ([EMAIL PROTECTED]) ____________________________________________________________________ MARGARET ROUSE, Associate Editor ([EMAIL PROTECTED]) ___________________________________________________________________ :::::::::::::::::::: ABOUT THIS NEWSLETTER ::::::::::::::::::::: Published by TechTarget (http://www.techtarget.com) TechTarget - The Most Targeted IT Media Copyright 2002, All Rights Reserved. Unsubscribe from 'Word of the Day' - Simply Reply to this Email with REMOVE within the Body or Subject > or - Go to: http://WhatIs.techtarget.com/register - Log in to edit your profile. - Click on the link to Edit email subscriptions. - Uncheck the box next to the newsletter you wish to unsubscribe from. - When finished, click "Save Changes to My Profile."
