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Topic: RC4 (cipher)


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RSA

  
  RC4 Page
A Practical Attack on Broadcast RC4, Mantin and Shamir, FSE 2001 - the main result mentioned in this paper, is the discovery of the exceptionally biased behavior of the second word of RC4 streams, which takes 0 with probability that is twice the expected (1/128 instead of 1/256).
Weaknesses in the Key Scheduling Algorithm of RC4, Fluhrer, Mantin and Shamir, SAC 2001 - this paper describes two weaknesses in the KSA of RC4 (the mechanism that extends a short key into a huge key of 1700 bits), denoted as the invariance weakness and the IV weakness.
The IV weakness, is related to a popular mode of operation of stream ciphers, where in order to avoid reusing the key, it is combined with a known vector (denoted the initialization vector or the IV) and this combination is used as the seed to the key stream generator.
www.wisdom.weizmann.ac.il /~itsik/RC4/rc4.html   (0 words)

  
  RC4 (cipher)
RC4 was initially a trade secret, but in September 1994 a description of it was anonymously posted to the Cypherpunks mailing list.
Like many such ciphers, it is essentially a pseudo-random number generator initialized from a secret key of up to 256 bytes.
The RC4 algorithm generates a "keystream" which is simply XORed with the plaintext to produce the ciphertext stream.
www.brainyencyclopedia.com /encyclopedia/r/rc/rc4__cipher_.html   (757 words)

  
 Definition of RC4 (cipher)
RC4 was designed by Ron Rivest of RSA Security in 1987; while it is officially termed "Rivest Cipher 4", the RC acronym is alternatively understood to stand for "Ron's Code" (see also RC2, RC5 and RC6).
RC4 generates a pseudorandom stream of bits (a "keystream") which, for encryption, is combined with the plaintext using XOR as with any Vernam cipher; decryption is performed the same way.
RC4 falls short of the standards set by cryptographers for a secure cipher in several ways, and thus is not recommended for use in new applications.
www.wordiq.com /definition/RC4_(cipher)   (1172 words)

  
 CipherSaber Home Page
A draft paper by Scott Fluhrer, Itsik Mantin and Adi Shamir was released on July 25, 2001 and announces new attacks on the RC4 cipher that is the basis for CipherSaber-1.
The CipherSaber-1 encryption algorithm is RC4 as published in the beginning of Chapter 17 of Applied Cryptography, Second Edition, by Bruce Schneier, John Wiley and Sons, New York, 1996.
The cipher key, which is the array K(i) in Schneier's notation, consists of the user key, in the form of an Ascii text string, followed by the ten byte initialization vector.
ciphersaber.gurus.com   (3401 words)

  
 Many man pages you need
RC4 consists of a key setup phase and the actual encryption or decryp- tion phase.
RC4() encrypts or decrypts the len bytes of data at indata using key and places the result at outdata.
Since RC4 is a stream cipher (the input is XORed with a pseudo-random key stream to produce the output), decryption uses the same function calls as encryption.
kjell.haxx.se /man/man.cgi?page=RC4§ion=3ssl   (253 words)

  
 Weak Keys in RC4
Although the RC4 algorithm has not been published by RSA Data Security, source code to implement the algorithm was anonymously posted to the Cypherpunks mailing list several months ago.
RC4 uses a variable length key from 1 to 256 bytes to initialize a 256-byte state table which is used for the subsequent generation of pseudo-random bytes.
This preliminary analysis of RC4 shows that the algorithm is vulnerable to analytic attacks based on statistical analysis of its state table.
marcel.wanda.ch /Archive/WeakKeys   (2800 words)

  
 RC4 - The pseudo-random generation algorithm PRGA
RC4 - The pseudo-random generation algorithm PRGA is one of the topics in focus at Global Oneness.
RC4 generates a pseudorandom stream of bits (a "keystream") which, for encryption, is combined with the plaintext using XOR as with any Vernam cipher; decryption is performed the same way.
RC4 falls short of the standards set by cryptographers for a secure cipher in several ways, and thus is not recommended for use in new applications.
www.experiencefestival.com /rc4_-_the_pseudo-random_generation_algorithm_prga   (0 words)

  
 RC4 in 4 lines of perl   (Site not responding. Last check: )
This cipher used to be trade secret of RSADSI, but some anonymous person distributed the source code on the internet last year.
Using RC4 in a commercial product without buying a license from RSADSI, whilst technically legal, would be impolite, and it is possible that RSADSI may take it upon themselves to reward you with a court case.
RC4 is a symmetric stream cipher and is fairly fast.
www.gregmiller.net /crypt/rc4.html   (365 words)

  
 Java & Stream Ciphers @ SYS-CON Media   (Site not responding. Last check: )
The reason you should understand cipher algorithms and their uses is not just to know how to use them, but to understand when to use them, their vulnerabilities, strengths, and how to develop your own algorithms.
RC4 is the de facto stream algorithm that was made public by an anonymous cypherpunk contributor in 1994.
Some of the places that a stream cipher may be a detriment would be using it for document files in which you wouldn't want plaintext and ciphertext lengths to match.
sys-con.com /read/37745.htm   (3655 words)

  
 ciphers
List ciphers with a complete description of proto- col version (SSLv2 or SSLv3; the latter includes TLS), key exchange, authentication, encryption and mac algorithms used along with any key size restrictions and whether the algorithm is classed as an "export" cipher.
Note that without the -v option, ciphers may seem to appear twice in a cipher list; this is when similar ciphers are available for SSL v2 and for SSL v3/TLS v1.
These cipher suites are vulnerable to a "man in the middle" attack and so their use is normally discouraged.
linuxcommand.org /man_pages/ciphers1.html   (889 words)

  
 Jail Cell RC4
The internal state of the keystream generator for generalized RC4 consists of a permutation table of an alphabet, S[0..m-1] (where m is the size of the alphabet), and two counters, i and j.
Because RC4 is a stream cipher and the same S-box configuration cannot be used to send more than one message, K needs to be modified for each message.
Since the cipher relies on human computation, there is likely to be a non-negligible rate of introduction of errors into the cipher.
www.mindflare.com /cipher/index.htm   (0 words)

  
 OpenSSL: Documents, rc4(3)
RC4 is a stream cipher with variable key length.
RC4 consists of a key setup phase and the actual encryption or decryption phase.
Since RC4 is a stream cipher (the input is XORed with a pseudo-random key stream to produce the output), decryption uses the same function calls as encryption.
www.openssl.org /docs/crypto/rc4.html   (0 words)

  
 [No title]
Example of RC4 output 4 Security Overview of RC4 The new passive ciphertext-only attack can find an arbitrarily long key in negligible time, which grows linearly (rather than exponentially) with the key size, and it gets even faster if WEP is replaced by its proposed successor WEP2.
RC4 was subjected to rigorous statistical test internally for 13 years and externally for 6 years, but this test typically consisted of taking a single stream with billions of output words, and counting the number of times each value occurred along it.
A simulation of the RC4 attack was created, this simulation showed that the attack was already able to recover the full key when given 256 probable resolved cases.
www.mcs.csuhayward.edu /~pwong/cs6520_sum03/rc4.doc   (1529 words)

  
 ciphers(1)   (Site not responding. Last check: )
List ciphers with a complete description of protocol version (SSLv2 or SSLv3; the latter includes TLS), key exchange, authentication, encryption and mac algorithms used along with any key size restrictions and whether the algorithm is classed as an "export" cipher.
Note that without the -v option, ciphers may seem to appear twice in a cipher list; this is when similar ciphers are available for SSL v2 and for SSL v3/TLS v1.
These cipher suites are vulnerable to a "man in the middle" attack and so their use is normally discouraged.
www.uni-bielefeld.de /cgi-bin/man.cgi?section=1&topic=ciphers   (884 words)

  
 Java & Stream Ciphers @ SYS-CON Media   (Site not responding. Last check: )
The reason you should understand cipher algorithms and their uses is not just to know how to use them, but to understand when to use them, their vulnerabilities, strengths, and how to develop your own algorithms.
RC4 is the de facto stream algorithm that was made public by an anonymous cypherpunk contributor in 1994.
Some of the places that a stream cipher may be a detriment would be using it for document files in which you wouldn't want plaintext and ciphertext lengths to match.
www.sys-con.com /read/37745.htm   (3736 words)

  
 rc4-amd64: RC4 implementation for AMD64   (Site not responding. Last check: )
Because of this, rc4-amd64 is not the "world's fastest RC4 implementation running on general purpose CPUs", as it was claimed in the conclusion.
RC4, or Arcfour, is one of the fastest stream cipher available.
RC4 implementations are not usually optimized for this mode, so they generally use a standard C language implementation.
etud.epita.fr /~bevand_m/papers/rc4-amd64.html   (1057 words)

  
 The RC4 algorithm within a COM component - The Code Project - C++ / MFC
The component is encapsulating the RC4 stream cipher algorithm, which is placed in separated source and header files (the rc4.cpp and rc4.h files).
When it was decided to use the RC4 algorithm then it was known that it wasn’t the hardest encryption that was chosen, but it needed to be a relative fast encryption.
When using the RC4 algorithm it is obvious that it will return a cipher text with the same length as the clear text.
www.codeproject.com /cpp/RC4CPP_DK.asp   (740 words)

  
 RC4(128) - phpMan   (Site not responding. Last check: )
rc4(3) OpenSSL rc4(3) NAME RC4_set_key, RC4 - RC4 encryption SYNOPSIS #include void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data); void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata, unsigned char *outdata); DESCRIPTION This library implements the Alleged RC4 cipher, which is described for example in Applied Cryptography.
RC4 consists of a key setup phase and the actual encryption or decryption phase.
SEE ALSO blowfish(3), des(3), rc2(3) HISTORY RC4_set_key() and RC4() are available in all versions of SSLeay and OpenSSL.
www.chedong.com /phpMan.php/man/RC4/128   (265 words)

  
 Comp 527: Assignment 4: Measuring RC4
stream cipher, internally generating a stream of random bits which is then XOR-ed with the plaintext.
RC4 in three lines of Perl site (which also includes a full, readable C version).
With a stream cipher like RC4, it should be the case that, if you toggle exactly one bit in the key, 50% of output bits should toggle.
www.cs.rice.edu /~dwallach/courses/comp527_s99/ass4.html   (903 words)

  
 Manual Page - RC4(3ssl)
Typically, 128 bit (16 byte) keys are used for strong encryption, but shorter insecure key sizes have been widely used due to export restrictions.
is a stream cipher (the input is XORed with a pseudo-random key stream to produce the output), decryption uses the same function calls as encryption.
Certain conditions have to be observed to securely use stream ciphers.
www.squarebox.co.uk /cgi-squarebox/manServer/usr/share/man/man3/RC4.3ssl   (208 words)

  
 doc.: IEEE 802.11-00/345
RC4 is used to generate a key stream, which is XORed against the ciphertext to reproduce plaintext.
RC4 is applied to the key schedule to produce a key stream the length of the packets encrypted payload.
Stream ciphers have a second property that is particularly important to the analysis: it is unsafe to use the same key twice, ever.
dim.com /~element/WepIns.html   (5632 words)

  
 RC4: Encyclopedia II - RC4 - History
RC4 was designed by Ron Rivest of RSA Security in 1987; while it is officially termed "Rivest Cipher 4", the RC acronym is alternatively understood to stand for "Ron's Code" (see also RC2, RC5 and RC6).
RC4 was initially a trade secret, but in September 1994 a description of it was anonymously posted to the Cypherpunks mailing list.
RC4 is often referred to as "ARCFOUR" (Alleged-RC4, because RSA has never officially released the algorithm), to avoid possible trademark problems.
www.experiencefestival.com /a/RC4_-_History/id/5403758   (0 words)

  
 RSA Laboratories - 3.6.3 What is RC4?
RC4 is a stream cipher designed by Rivest for RSA Data Security (now RSA Security).
It is a variable key-size stream cipher with byte-oriented operations.
RC4 is used for file encryption in products such as RSA SecurPC (see Question 5.2.4).
www.rsasecurity.com /rsalabs/node.asp?id=2250   (0 words)

  
 Hogosha - Advanced RC4 Stream Cipher File Encryption Utility
RC4 is very strong and difficult to break with a strong enough passphrase.
RC4 is a stream cipher designed by Rivest for RSA Data Security (now RSA Security).
Analysis shows that the period of the cipher is overwhelmingly likely to be greater than 10^100.
www.voodoofiles.com /4151   (305 words)

  
 The SPS Weblog - VFPEncryption.FLL Update
The RC4 stream cipher that has been added is very useful in encrypting/decrypting fields in a table.
Because it is a stream cipher, the resulting ciphertext (encrypted data) is the same length as the plaintext.
Unlike a block cipher (which comprises all of the other ciphers that vfpencryption.fll provides), a stream cipher does not pad the results with extra characters.
www.sweetpotatosoftware.com /SPSBlog/PermaLink,guid,5d4a0cf0-7d1d-4353-a49b-667946ff1c81.aspx   (1660 words)

  
 Schneier on Security: Microsoft RC4 Flaw
One of the most important rules of stream ciphers is to never use the same keystream to encrypt two different documents.
The stream cipher RC4 [9] with key length up to 128 bits is used in Microsoft Word and Excel to protect the documents.
Since each record in the file reused the same RC4 stream, the first 20 bytes of each password record could be recovered with pencil and paper.
www.schneier.com /blog/archives/2005/01/microsoft_rc4_f.html   (1808 words)

  
 What are block and stream ciphers?
DES is a block cipher with a 64 bit block size.
A5, the algorithm used to encrypt GSM communications, is a stream cipher.
The RC4 cipher and the one-time pad are also stream ciphers.
www.tech-faq.com /block-stream-cipher.shtml   (152 words)

  
 RbCafe :: Programmation & Cryptography :: » Rc4 Set Key
RC4 is a stream cipher with variable key length.
RC4 consists of a key setup phase and the actual encryption or decryp-
RC4() encrypts or decrypts the len bytes of data at indata using key
www.rbcafe.com /rc4-set-key.html   (198 words)

  
 TCLLIB - Tcl Standard Library: rc4
This package is an implementation in Tcl of the RC4 stream cipher developed by Ron Rivest of RSA Data Security Inc. The cipher was a trade secret of RSA but was reverse-engineered and published to the internet in 1994.
The data to be processes can be specified either as a string argument to the rc4 command, or as a filename or a pre-opened channel.
Instead the command provided is called with the rc4 result data appended as the final parameter.
tcllib.sourceforge.net /doc/rc4.html   (416 words)

  
 perl rc4
This cipher used to be trade secret of RSADSI, but some anonymous person distributed the source code on the Internet in 1994.
In theory you could use RC4 in a commercial product without buying a license from RSADSI, but it is possible that RSADSI may make legal threats.
Some people are calling RC4 ARC4 (Alleged RC4) to avoid using RC4 which is probably a trademark.
www.cypherspace.org /adam/rsa/rc4.html   (694 words)

  
 Cryptanalysis of CipherSaber-1   (Site not responding. Last check: )
CipherSaber 1 is a way of using Ron Rivest's RC4 cipher as a practical symmetric key cryptosystem.
To prevent the same RC4 key from being used twice, a ten byte initialization vector (IV) is appended to the user key to form the complete RC4 key.
It might be better for each user to determine the largest value of N that is tollerable on their computer and to agree to use the smaller of the two acceptable N values when communicating with another CipherSaber user.
ciphersaber.gurus.com /cryptanalysis.html   (2552 words)

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