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Topic: Chaffing and winnowing


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In the News (Wed 3 Dec 08)

  
 [No title]   (Site not responding. Last check: 2007-10-04)
Chaffing and Winnowing: Confidentiality without Encryption Ronald L. Rivest MIT Lab for Computer Science March 18, 1998 (rev. April 24, 1998) http://theory.lcs.mit.edu/~rivest/chaffing.txt A major goal of security techniques is ``confidentiality''---ensuring that adversaries gain no intelligence from a transmitted message.
With chaffing and winnowing, the adversary may know (or suspect) that there are two different kinds of packets, but he is unable to distinguish them because he does not possess the secret authentication key.
Chaffing and winnowing differ in that the two parties involved may not even explicitly take any steps to achieve confidentiality (if someone else is adding the chaff).
theory.lcs.mit.edu /~rivest/chaffing.txt   (3360 words)

  
 Chaffing and winnowing
Chaffing and winnowing is separation of chaff from grain, done by a threshing machine; the phrase is also used metaphorically.
Chaffing and winnowing is a cryptography technique, though as it works by hiding which part of a transmission is the message, it is classified as steganography.
A message is broken into blocks, and each one is transmitted with a message authentication code[?], interspersed at random with other similar blocks, called chaff.
ebroadcast.com.au /lookup/encyclopedia/ch/Chaffing_and_winnowing.html   (90 words)

  
 Chaffe - Chaffing and Winnowing.
The format of the tuples is simple, but adds additional fluff to the chaffed text size, since I'm hoping to keep this as portable as possible (yes, this is a string).
You can save chaffed information in a file, or email it without further groveling over your results, although any but the shortest messages may be a bit ridiculous to send by email.
Winnow the text (or text in the specified file), returning the wheat.
www.medsch.wisc.edu /~annis/creations/Chaffe.pm.html   (400 words)

  
 Confidentiality Using Authentication
One technique for providing confidentiality using authentication is called ``chaffing and winnowing'' and was first implemented by Ronald Rivest of MIT's Laboratory for Computer Science [2].
The word winnow means to separate or eliminate useless parts and is derived from its common meaning, to separate wheat from chaff (useless plant parts) on a farm.
All-or-nothing transforms make chaffing and winnowing more efficient because the receiver must know exactly which packets are part of the message in order to read the message.
www.acm.org /crossroads/xrds5-2/confide.html   (1706 words)

  
 Chaffinch: Confidentiality in the Face of Legal Threats
Chaffing and winnowing was proposed by Rivest [10] as a way of providing confidentiality using only authentication primitives.
This is exactly the property that "chaffing and winnowing" requires, since it means that an attacker has to guess exactly which sections of the data stream correspond to the message in order to get a decoding that generates anything other than random bits.
In a "chaffing and winnowing" scheme these block numbers are all relatively small integers so that insufficient randomness may be injected to completely defeat an attacker who attempts to construct dictionaries of blocks at each position.
www.cl.cam.ac.uk /~rnc1/Chaffinch.html   (6647 words)

  
 Rivest's Chaffing and Winnowing
Rivest's M.I.T. Web site (http://theory.lcs.mit.edu/~rivest/chaffing.txt), is described as "chaffing and winnowing" digital information instead of encrypting it.
Rivest's paper, it is possible to hide a message by breaking it into packets that are then secretly identified as good information, or "wheat," and gibberish, or "chaff," in such a way that an eavesdropper cannot distinguish the two.
The strength of the idea for chaffing and winnowing is that it is possible to prove mathematically that a message cannot be decoded, Mr.
www.chiark.greenend.org.uk /pipermail/ukcrypto/1998-March/001419.html   (639 words)

  
 [No title]
Chaffing and Winnowing: Confidentiality without Encryption Ronald L. Rivest MIT Lab for Computer Science March 18, 1998 (rev. July 1, 1998) http://theory.lcs.mit.edu/~rivest/chaffing.txt A major goal of security techniques is ``confidentiality''---ensuring that adversaries gain no intelligence from a transmitted message.
(Variations on chaffing and winnowing, such as omitting the plaintext bits altogether and letting the receiver infer them from the MAC's, destroy these nice properties.) I note that the use of MAC's can be replaced by digital signatures.
In the chaffing and winnow approach, Alice and Bob use standard authentication techniques, and then someone adds chaff to the sequence of authenticated packets.
theory.lcs.mit.edu /~rivest/chaffing-980701.txt   (3573 words)

  
 Chaffing and Winnowing - Wikipedia
Der Spreu-und-Weizen-Algorithmus, auch Chaffing and Winnowing (englisch to winnow the chaff from the wheat – die Spreu vom Weizen trennen) ist ein Verfahren zur Geheimhaltung beim Versenden von Daten, ohne dass die Daten dabei verschlüsselt werden.
Chaffing and Winnowing ist eine Alternative zu Steganographie und Kryptographie.
Mit Chaffing and Winnowing wird zwar der Umfang der übermittelten Botschaft vergrößert, aber es scheint, wenn die Datenpakete klein genug sind, eine hohe Sicherheit zu bieten, ohne dass dabei eine Verschlüsselung der Daten vorgenommen wird.
de.wikipedia.org /wiki/Chaffing_and_Winnowing   (434 words)

  
 Larry Adams "Fraud In Other Words" Nov 2006 2D Barcode, Puffery, Avoision, Fungible Asset, Cammer
Chaffing and winnowing is a form of steganography.
For chaffing and winnowing, the sender and the intended receiver share a “message authentication code” (MAC), which is unknown to law enforcement or anyone else who might tap into the communications channel.
Winnowing was developed for agricultural purposes by ancient cultures.
www.larry-adams.com /200611_article.htm   (1825 words)

  
 Dr. Dobb's | Swaine's Flames | July 22, 2001   (Site not responding. Last check: 2007-10-04)
Things to note: The Chaffing and Winnowing process is based on authentication technology, which is not regarded by the U.S. Government as encryption and is legal for export.
The Chaffing and Winnowing process is neither encryption nor steganography, the two main ways of achieving confidentiality today, but a totally new method of privacy protection.
Chaffing and Winnowing appears to be entirely legal, with no existing provision for governmental access to the plaintext messages.
www.ddj.com /184410603   (928 words)

  
 chaffing and winnowing - a Whatis.com definition
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).
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).
whatis.techtarget.com /gDefinition/0,294236,sid44_gci786707,00.html   (274 words)

  
 [No title]
Suppose Alice adopts a public-key chaffing and winnowing system, as follows: To send a message to Bob, she tacks Bob's public key to the plaintext before using MD5.
Alice decides that to communicate with winnowing and chaffing she will stick to using secret keys.
The format of each message is: (M, h) where M is the plaintext message block and h is the hash code generated by applying MD5 to M with k appended to it, where k is a secret key.
pages.slc.edu /~msiff/courses/crypto/assignments/hw10.html   (799 words)

  
 CHAFFING AND WINNOWING: CONFIDENTIALITY WITHOUT ENCRYPTION, by Ronald L. Rivest
This paper introduces a new technique, which we call "chaffing and winnowing" — to winnow is to "separate out or eliminate (the poor or useless parts)," (Webster's Dictionary), and is often used when referring to the process of separating grain from chaff.
She might pre-process the message using an "all-or-nothing" or "package transform" (Rivest 1997) — this is a keyless (non-encryption) transform that takes the message and produces a "packaged message" with the property that the recipient (Bob) can't produce the original message unless he has received the entire packaged message.
Thanks to my dad for suggesting the term "winnowing," to Mark Lomas for noting that multiplexing two streams may allow each to serve as chaff for the other, and to Peter Wayner for suggesting the relationship to deniable encryption.
reactor-core.org /chaffing-and-winnowing.html   (3592 words)

  
 AttackPrevention :: Cryptology: Whitepapers and Tools   (Site not responding. Last check: 2007-10-04)
This paper presents an overview of Chaffing and Winnowing as described by Ronald Rivest.
Chaffing and Winnowing introduces a novel new concept that does not use encryption keys, and as such would not be subject to import and export restrictions.
Chaffing and Winnowing achieves privacy and confidentiality by using authentication keys, however, these are not to be confused with encryption keys.
www.attackprevention.com /Cryptology/4   (1081 words)

  
 Chaffing and winnowing - Wikipedia, the free encyclopedia
It can be viewed as a form of steganography.
One variant of the technique is to continuously send out packets to multiple recipients: the participants who get chaff simply ignore it; this helps protect against information leakage and traffic analysis.
The name of the technique is derived from agriculture: after a cereal crop is harvested and threshed it remains mixed together with fibrous chaff, and must be separated out by a step of winnowing.
en.wikipedia.org /wiki/Chaffing_and_winnowing   (258 words)

  
 Chaffing and Winnowing
An example of a technology that may be a way around existing encryption legislation is Chaffing and Winnowing.
Winnowing means to remove the useless parts, or "chaff", from grain.
Chaffing and Winnowing is new and unproven, but it isn't fantasy: It has been proposed by none other than Ron Rivest, an inventor of the RSA encryption algorithm and a professor at MIT.
www.networkworld.com /newsletters/sec/1206sec1.html   (962 words)

  
 Chaffing and Winnowing   (Site not responding. Last check: 2007-10-04)
"Chaffing and winnowing" is a privacy-enhancement scheme without encryption.
It consists of adding false packets to a message at the source (chaffing), and then removing the false packets at the destination (winnowing).
The sender breaks the message into packets, and authenticates each packet, in which the "message authentication code" or "MAC" is computed as a function of the packet contents and the secret authentication key.
www.javvin.com /networksecurity/ChaffingWinnowing.html   (115 words)

  
 Steganography and Digital Watermarking Bibliography
Chaffing and Winnowing: Confidentiality without Encryption (March 1998), MIT, Internal Paper.
Chaffing and Winnowing: Confidentiality without Encryption Ronald L. Rivest MIT Lab for Computer Science March 23, 1998 http://theory.lcs.mit.edu/~rivest/chaffing.txt A major goal of security techniques is ``confidentiality''---ensuring that adversaries gain no intelligence from a transmitted message.
This depends on how the original message is broken into packets, and how the chaffing is done.
www.jjtc.com /Steganography/bib/3000053.htm   (2860 words)

  
 [No title]
6 Implementation The weakness in Chaffing and Winnowing, I found, is possible as soon as there is a protocol mechanism to react on missing packets.
7 Conclusion Although there is a weakness in the concept of chaffing and winnowing, it is forseeable, and can be compensated with a minimal effort.
I personally hope that there are no more weaknesses in Chaffing and Winnowing.
www3.futureware.at /artikel/paper1.txt   (1047 words)

  
 Schwartz, Neil, How Emerging Technologies Threaten the U.S. Government's Encryption Regulatory Scheme, 3 W. Va. J. L. ...   (Site not responding. Last check: 2007-10-04)
Part III asserts that emerging technologies, like steganography and 'chaffing and winnowing' may ultimately render the encryption debate moot.
This Note concludes by suggesting that government efforts to control the proliferation of encryption technology are unnecessary because other emerging technologies pose far greater surveillance and enforcement challenges for the law enforcement community.
Steganography and 'chaffing and winnowing' are poised to grow in importance if governments attempt to regulate, or even prohibit, the use of encryption technology.
www.wvu.edu /~law/wvjolt/Arch/Schwar/Schwar.htm   (5609 words)

  
 Wired News: A Work-Around for Crypto Export Restrictions
Ronald Rivest, relying on an ancient threshing floor analogy, calls his process chaffing and winnowing.
Using his technique, messages are sent on the Net in a combination of good packets (wheat) and bad packets (chaff).
Rivest notes that authenticating data is not considered encryption, and thus his chaffing and winnowing process would avoids US restrictions on the export of encryption technology.
www.wired.com /news/business/1,11127-0.html   (318 words)

  
 Science News Online - Letters - 6/27/98
However, one may argue that chaffing and winnowing, viewed large, is cryptography: A sender inserts a message and key into a fl box at one end, producing unintelligible output; the recipient inserts this output and key into the fl box and gets the message at the other end.
You and I could just as easily prearrange a system of winks and nods to tell each other when we were telling the truth and when we were lying and then carry on a secret conversation entirely in the open.
The difference between winks and nods, chaffing and winnowing is just a matter of degree.
www.sciencenews.org /pages/sn_arc98/6_27_98/letters.htm   (386 words)

  
 Seperating the wheat from the chaff...   (Site not responding. Last check: 2007-10-04)
An MIT professor has proposed a new method of providing for secure data exchange on the Internet - one that uses a technique that he argues lies outside the control of US officials struggling to maintain a tight hold on encryption enabled software.
, and thus his chaffing and winnowing process would avoid US restrictions on the export of encryption technology.
Rivest's paper, reported in Sunday's New York Times, has a clear political point: "As a consequence of the existence of chaffing and winnowing," he writes, "one can argue that attempts by law enforcement to regulate confidentiality by regulating encryption must fail, as confidentiality can be obtained effectively without encryption."
cbc.am /chaff.htm   (202 words)

  
 chaffing - OneLook Dictionary Search
Tip: Click on the first link on a line below to go directly to a page where "chaffing" is defined.
Chaffing : Online Plain Text English Dictionary [home, info]
chaffing : Webster's Revised Unabridged, 1913 Edition [home, info]
www.onelook.com /?w=chaffing   (122 words)

  
 Chaffing&Winnowing
The original reason Ron created chaffing and winnowing was to show that encryption laws are useless.
Even more, even if the government demands that the plaintext be in the open, his original paper was set up to pass even that egregious requirement.
In fact, it bears very little resemblance to the name "chaffing and winnowing." It would not matter to them wether you were using DES, IDEA, or C&W. If it looks like a duck, walks like a duck, and quacks like a duck...
www.argo.es /~jcea/artic/chaffing.htm   (3261 words)

  
 Chaffing   (Site not responding. Last check: 2007-10-04)
Chaffing, in the information technology, is the process of adding poor or useless part (chaff) to a packet.
Winnowing is the reverse: to separate out or eliminate the poor or useless parts from the packet.
The technique consists of adding false packets to a message at the source, and then removing the false packets at the destination.
www.javvin.com /networksecurity/Chaffing.html   (81 words)

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