|
| |
| | Block cipher - Wikipedia, the free encyclopedia |
 | | Lucifer is generally considered to be the first civilian block cipher, developed at IBM in the 1970s based on work done by Horst Feistel. | | | An early and highly influential block cipher design was the Data Encryption Standard (DES), developed at IBM and published as a standard in 1977. | | | When encrypting, a block cipher might take a (for example) 128-bit block of plaintext as input, and output a corresponding 128-bit block of ciphertext. |
|
http://en.wikipedia.org/wiki/Block_cipher
(937 words)
|
|
| |
| | Talk: Cryptography - Open Encyclopedia |
| | ciphers have the potential to be vastly different algorithmically; codes are always performed by table lookup. | | | But a "cipher" is a general class of algorithm, and "code" isn't, it's just one algorithm (table lookup) Matt 07:49, 17 Mar 2004 (UTC) | | | I think a code and a cipher refer to two different ways of implementing a mathematical transform; codes are lookups, ciphers are procedural. |
|
http://talk.open-encyclopedia.com/Cryptography
(11340 words)
|
|
| |
| | Block cipher modes of operation - Wikipedia, the free encyclopedia |
| | With cipher feedback a keystream block is computed by encrypting the previous ciphertext block. | | | It would be observed, for example, that a one-block error in the transmitted ciphertext would result in a one-block error in the reconstructed plaintext for ECB mode encryption, while in CBC mode such an error would affect two blocks: | | | Because a block cipher works on units of a fixed size, but messages come in a variety of lengths, some modes (mainly CBC) require that the final block be padded before encryption. |
|
http://en.wikipedia.org/wiki/Cipher_Block_Chaining
(1174 words)
|
|
| |
| | Block cipher modes of operation - Wikipedia, the free encyclopedia |
| | With cipher feedback a keystream block is computed by encrypting the previous ciphertext block. | | | It would be observed, for example, that a one-block error in the transmitted ciphertext would result in a one-block error in the reconstructed plaintext for ECB mode encryption, while in CBC mode such an error would affect two blocks: | | | Because a block cipher works on units of a fixed size, but messages come in a variety of lengths, some modes (mainly CBC) require that the final block be padded before encryption. |
|
http://en.wikipedia.org/wiki/Cipher_Block_Chaining
(1173 words)
|
|
| |
| | FIPS 81 - Des Modes of Operation |
| | In a block method, the DES input block is (or is a simple function of) the plain text to be encrypted and the DES output block is the cipher text. | | | The input block is processed through a DES device in the encrypt state, and the resulting output block is used as the cipher text, i.e., (C1,C2,... | | | CBC is a block cipher system in which the first plain text data block is exclusive-ORed with a block of pseudo-random data prior to being processed through the DES. |
|
http://www.thc.org/root/docs/cryptography/fips81.html
(6653 words)
|
|
| |
| | S-1 - MindSharer Article Archive |
| | In cryptography, the S-1 block cipher was a block cipher posted in source code form on Usenet on 11 August 1995. | | | Although incorrect security markings immediately indicated a hoax, there were several features of the code which suggested it might be leaked source code for the Skipjack encryption algorithm, which was still classified at the time. |
|
http://articles.mindsharer.com/html/S-1
(125 words)
|
|
| |
| | United States Patent Application: 0020071552 |
| | The method of claim 1, wherein generating the sequence of offsets involves: computing a key-variant by enciphering a constant with the block cipher, wherein the block cipher is keyed by the given key; and computing the sequence of offsets as a function of the key variant and the nonce. | | | The method of claim 1, wherein computing the ciphertext fragment involves: computing a precursor pad as a function of an offset and the length of the message; computing a pad by applying the block cipher to the precursor pad; and computing the ciphertext fragment by combining the message fragment and the pad. | | | The method of claim 1, wherein computing the tag involves: computing a checksum as a function of the message, the ciphertext fragment, and the sequence of offsets; and computing the tag as a function of the checksum, the key, and an offset. |
|
http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=2&f=G&l=50&co1=AND&d=PG01&s1=rogaway.IN.&OS=IN/rogaway&RS=IN/rogaway
(10240 words)
|
|
| |
| | wikien.info: Main_Page |
| | Consequently these ciphers should be viewed as academic efforts to advance the field of block cipher design, rather than algorithms. | | | The ciphers were developed based on a body of work analysing DES, and are very similar to DES in structure. | | | Like DES, it is a 16-round Feistel cipher and has a similar general structure, but differs in the choice of the particular S-boxes, the "P-permutation", and the "Expansion permutation". |
|
http://pardus.info/index.php?title=Loki
(698 words)
|
|
| |
| | Block cipher - definition of Block cipher in Encyclopedia |
| | Lucifer is generally considered to be the first civilian block cipher, developed at IBM in the 1970s based on work done by Horst Feistel. | | | A list of many symmetric algorithms, the majority of which are block ciphers. | | | In cryptography, a block cipher is a type of symmetric key cipher which operates on groups of bits of a fixed length, termed blocks. |
|
http://encyclopedia.laborlawtalk.com/Block_cipher
(791 words)
|
|
| |
| | RSA Security - 2.1.4 What is a block cipher? |
| | A block cipher is a type of symmetric-key encryption algorithm that transforms a fixed-length block of plaintext (unencrypted text) data into a block of ciphertext (encrypted text) data of the same length. | | | More information about block ciphers and the various available algorithms can be found in almost any book on contemporary cryptography. | | | For those with a mathematical background (see Appendix A): Since different plaintext blocks are mapped to different ciphertext blocks (to allow unique decryption), a block cipher effectively provides a permutation (one to one reversible correspondence) of the set of all possible messages. |
|
http://www.rsasecurity.com/rsalabs/node.asp?id=2168
(342 words)
|
|
| |
| | Crypt::CBC - Encrypt Data with Cipher Block Chaining Mode |
| | This module is a Perl-only implementation of the cryptographic cipher block chaining mode (CBC). | | | The CBC algorithm must buffer data blocks inernally until they are even multiples of the encryption algorithm's blocksize (typically 8 bytes). | | | This could be improved by implementing this module in C. It may also be worthwhile to optimize the DES and IDEA block algorithms further. |
|
http://perl.enstimac.fr/perl5.6.1/site_perl/5.6.1/Crypt/CBC.html
(1182 words)
|
|
| |
| | Mars (planet) - encyclopedia article about Mars (planet). |
| | Camellia In cryptography, Camellia is a block cipher that has been evaluated favorably by several organisations, including the European Union's NESSIE project (a selected algorithm), and the Japanese CRYPTREC project (a recommended algorithm). | | | When encrypting, a block cipher might take a (for example) 128-bit block of plaintext as input, and output a corresponding 128-bit block of ciphertext. | | | CS-Cipher In cryptography, the CS-Cipher is a block cipher invented by Jacques Stern and Serge Vaudenay in 1998. |
|
http://encyclopedia.thefreedictionary.com/Mars+(planet)
(6065 words)
|
|
| |
| | rfc2405.txt |
| | Introduction This document describes the use of the DES Cipher algorithm in Cipher Block Chaining Mode as a confidentiality mechanism within the context of the Encapsulating Security Payload. | | | In CBC mode, the "effective plaintext" for an encryption is the XOR of the actual plaintext and the ciphertext of the preceeding block. | | | Abstract This document describes the use of the DES Cipher algorithm in Cipher Block Chaining Mode, with an explicit IV, as a confidentiality mechanism within the context of the IPSec Encapsulating Security Payload (ESP). |
|
http://www.rfc-editor.org/rfc/rfc2405.txt
(2271 words)
|
|
| |
| | Block cipher modes of operation - Wikipedia, the free encyclopedia |
| | With cipher feedback a keystream block is computed by encrypting the previous ciphertext block. | | | It would be observed, for example, that a one-block error in the transmitted ciphertext would result in a one-block error in the reconstructed plaintext for ECB mode encryption, while in CBC mode such an error would affect two blocks: | | | Because a block cipher works on units of a fixed size, but messages come in a variety of lengths, some modes (mainly CBC) require that the final block be padded before encryption. |
|
http://en.wikipedia.org/wiki/Cipher_Block_Chaining
(1173 words)
|
|
| |
| | Key controlled block-cipher cryptographic system employing a multidirectional shift matrix - Patent 4195200 |
| | For example, a square matrix, i.e., 8 by 8 has been disclosed as this is a conventional byte size in many classes of computer systems and is accordingly a convenient data block to utilize in such a block cipher cryptographic system. | | | If the test in block 3 had resulted in "no", the system would have proceeded to block 6, which in addition to loading the array 10 with a new block of data to be transformed, would concurrently cause the current contents of the array to be gated to the output memory buffer. | | | Block 4 proceeds to block 5 which causes the previously reset first block flag to be set to a one so that the system will know that the next round is not a first block operation, so that the system can proceed to block 6 via the test made at block 3. |
|
http://www.freepatentsonline.com/4195200.html
(10498 words)
|
|
| |
| | FIPS 81 - Des Modes of Operation |
| | In a block method, the DES input block is (or is a simple function of) the plain text to be encrypted and the DES output block is the cipher text. | | | The input block is processed through a DES device in the encrypt state, and the resulting output block is used as the cipher text, i.e., (C1,C2,... | | | Cipher text representing a partial data block must be decrypted in a manner as specified for the application. |
|
http://www.itl.nist.gov/fipspubs/fip81.htm
(6653 words)
|
|
| |
| | 95082301.HTM |
| | In contrast, in a good block cipher, every input bit is diffused throughout the block, even to "earlier" bits. | | | This means that a block cipher can take advantage of any and all of the uniqueness in a plaintext block. | | | Ciphers which depend on algorithmic operations -- even nonlinear operations -- seem more likely to be vulnerable to attack than ciphers which contain massive internal state. |
|
http://www.ciphersbyritter.com/NEWS/95082301.HTM
(688 words)
|
|
| |
| | diamond2.doc |
| | An ideal 128 bit block cipher would use a z bit key to select one of 2z functions from the set of all one to one and onto functions that map one input block of 128 bits to one output block of 128 bits. | | | The Diamond2 Block Cipher is the same as the Diamond, MPJ and MPJ2 Encryption Algorithms, with the exception of the key expansion algorithm. | | | This block cipher may be implemented in hardware or software. |
|
http://www.cygnusproductions.com/downloads/pc/diamond2.doc
(4861 words)
|
|
| |
| | Programming Libraries Science, Directory |
| | Botan An open-source C++ crypto library that includes block and stream ciphers, hash functions, MACs, and public key algorithms, along with an easy to use filter-based interface. | | | Snapcrypt - Cryptography Algorithms A library for the TMS320C54x DSP, contains algorithms for symmetric block ciphers, one-way hash functions, public key encryption and digital signature. | | | Catacomb Cryptographic Library Library of cryptographic primitives in ANSI C, including block ciphers and hash functions, together with generic modes of operation. |
|
http://www.wacofdn.org/d2RjXzgyMTQ2.aspx
(655 words)
|
|
| |
| | 56221.010802&ELEMENT_SET=DECL |
| | block cipher using a secret first key ; a third component for assembling the plurality of ciphertext segments into a ciphertext string ; and a fourth component for outputting the ciphertext string. | | | 25 and the plurality of ciphertext blocks 22 form the ciphertext string y 24 that has n+2 blocks and is the output data of the encryption scheme 50. | | | In a further aspect of the present invention, the step is provided of performing the deciphering step with the inverse of a block cipher using a secret first key, the block cipher and the secret first key being the same as to those used at the message encryption method using the plurality of processors. |
|
http://www.wipo.int/cgi-pct/guest/getbykey5?KEY=01/56221.010802&ELEMENT_SET=DECL
(7515 words)
|
|
| |
| | RSA Security - 2.1.4 What is a block cipher? |
| | A block cipher is a type of symmetric-key encryption algorithm that transforms a fixed-length block of plaintext (unencrypted text) data into a block of ciphertext (encrypted text) data of the same length. | | | More information about block ciphers and the various available algorithms can be found in almost any book on contemporary cryptography. | | | For those with a mathematical background (see Appendix A): Since different plaintext blocks are mapped to different ciphertext blocks (to allow unique decryption), a block cipher effectively provides a permutation (one to one reversible correspondence) of the set of all possible messages. |
|
http://www.rsasecurity.com/rsalabs/node.asp?id=2168
(342 words)
|
|
| |
| | mutation.txt |
| | The enciphering/deciphering functions are such that every bit in the output block depends jointly on every bit in the input block and on every bit in the password. | | | By using Mutation's Cipher Block Chaining option it is possible to use DES in such a manner that identical eight-byte plaintext blocks virtually always yield different ciphertext blocks, without altering the security of the existing algorithm. | | | Repetitions of some other blocks may also be visible; for example, telephone numbers in the plain text when aligned with the eight-byte DES blocks, can be recognized as identical in the ciphertext. |
|
http://www.textfiles.com/computers/DOCUMENTATION/mutation.txt
(2721 words)
|
|
| |
| | OpenSSL: Documents, EVP_EncryptInit(3) |
| | A random block has better than 1 in 256 chance of being of the correct format and problems with the input data earlier on will not produce a final decrypt error. | | | If the cipher is a fixed length cipher then attempting to set the key length to any value other than the fixed value is an error. | | | For example if the block size is 8 and 11 bytes are to be encrypted then 5 padding bytes of value 5 will be added. |
|
http://www.openssl.org/docs/crypto/EVP_EncryptInit.html
(2292 words)
|
|
| |
| | Cipher feedback mode |
| | Bit errors in the incoming cipher block (bytes in this context) will cause bit error at the same bit positions in the first plain text block. | | | This cipher block will then be fed to the shift register and cause bit errors in the plain text for as long as the erroneous bits stay in the shift register. | | | In the Cipher Feedback Mode (CFB) is data encrypted in units smaller than the block size. |
|
http://www.pvv.ntnu.no/~asgaut/crypto/thesis/node16.html
(342 words)
|
|
| |
| | Schneier on Security: May 2005 Archives |
| | There are two ways to look at a cryptographic primitive: block cipher, digital signature function, whatever. | | | Differential and linear cryptanalysis are good examples of this: high-powered mathematical tools that can be used to break different block ciphers. | | | For those of you who don't know, timing attacks are an example of side-channel cryptanalysis: cryptanalysis using additional information about the inner workings of the cryptographic algorithm. |
|
http://www.schneier.com/blog/archives/2005/05
(7451 words)
|
|
| |
| | HMAC (FIPS 198); Keyed-Hash Message Authentication Code (HMAC) dated March 6, 2002 |
| | CCM is based on an approved symmetric key block cipher algorithm whose block size is 128 bits, such as the Advanced Encryption Standard (AES) algorithm currently specified in Federal Information Processing Standard (FIPS) Pub. | | | The testing requirements for this algorithm can be found in the document titled The Counter with Cipher Block Chaining-Message Authentication Code (CCM) Validation System (CCMVS). | | | The Counter with Cipher Block Chaining-Message Authentication Code (CCM) is specified in Special Publication 800-38C dated May, 2004, Counter with Cipher Block Chaining-Message Authentication Code (CCM). |
|
http://csrc.nist.gov/cryptval/MsgAuth.htm
(372 words)
|
|
| |
| | Manpage of TclDESjr |
| | Due to the nature of the OFB and CFB modes of DES, the message/cipher data is considered to be a stream of bits, not blocks of bytes. | | | All four DES modes are supported: Electronic Code Block (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), and Output Feedback (OFB). | | | The output is a binary string of the decrypted form of ciphertext. |
|
http://tcldes.sourceforge.net/tcldesjr.html
(1300 words)
|
|
| |
| | MMB - the free encyclopedia |
| | In cryptography, MMB (Modular Multiplication-based Blockcipher) is a block cipher designed by Joan Daemen as an improved replacement for the IDEA cipher. | | | Daemen, R. Govaerts, and J. Vandewalle, "Block Ciphers Based on Modular Arithmetic, " Proceedings of the 3rd Symposium on:State and Progress of Research in Cryptography, Fondazione Ugo Bordoni, 1993, pp. | | | Weaknesses in the key schedule were identified by EliBiham, and this, together with the fact that the cipher had not been designed to resist linear cryptanalysis, meant that other designs were pursued instead, such as 3-Way. |
|
http://www.world-knowledge-encyclopedia.com/?t=MMB
(115 words)
|
|
|
