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MUGI
In cryptography, MUGI is a pseudorandom number generator (PRNG) designed for use as a stream cipher. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003, however, has been dropped to "candidate" by CRYPTREC revision in 2013. MUGI takes a 128-bit secret key and a 128-bit initial vector (IV). After a key- and IV- setup process, MUGI outputs 64-bit output strings based on the internal state, while updating the internal state after each output block. MUGI has a 1216-bit internal state; there are three 64-bit registers (the "state") and 16 64-bit registers (the "buffer"). MUGI uses the non-linear S-box that was originally defined in Advanced Encryption Standard (AES). A part of the linear transformation also reuses the MDS matrix of AES. The basic design is influenced by that of Panama. Security As of September 2006, there are no known attacks against MUGI that are faster than serial brute-force of the key space or of the interna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bart Preneel
Bart Preneel (born 15 October 1963 in Leuven, Belgium) is a Flemish cryptographer and cryptanalyst. He is a professor at Katholieke Universiteit Leuven, in the COSIC group. He was the president of the International Association for Cryptologic Research in 2008-2013 and project manager of ECRYPT. Education In 1987, Preneel received an electrical engineering degree in applied science from the Katholieke Universiteit, Leuven. In 1993, Preneel received a PhD from the Katholieke Universiteit Leuven. His dissertation in computer science, entitled ''Analysis and Design of Cryptographic Hash Functions'', was advised by Joos (Joseph) P. L. Vandewalle and René J. M. Govaerts. Career Along with Shoji Miyaguchi, he independently invented the Miyaguchi–Preneel scheme, a complex structure used in the hash function Whirlpool. He is one of the authors of the RIPEMD-160 hash function. He was also a co-inventor of the stream cipher MUGI which would later become a Japanese standard, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream, to give a digit of the ciphertext stream. Since encryption of each digit is dependent on the current state of the cipher, it is also known as ''state cipher''. In practice, a digit is typically a bit and the combining operation is an exclusive-or (XOR). The pseudorandom keystream is typically generated serially from a random seed value using digital shift registers. The seed value serves as the cryptographic key for decrypting the ciphertext stream. Stream ciphers represent a different approach to symmetric encryption from block ciphers. Block ciphers operate on large blocks of digits with a fixed, unvarying transformation. This distinction is not always clear-cut: in some modes of operation, a block cipher primitive is used in such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRYPTREC
CRYPTREC is the Cryptography Research and Evaluation Committees set up by the Japanese Government to evaluate and recommend cryptographic techniques for government and industrial use. It is comparable in many respects to the European Union's NESSIE project and to the Advanced Encryption Standard process run by National Institute of Standards and Technology in the U.S. Comparison with NESSIE There is some overlap, and some conflict, between the NESSIE selections and the CRYPTREC draft recommendations. Both efforts include some of the best cryptographers in the world therefore conflicts in their selections and recommendations should be examined with care. For instance, CRYPTREC recommends several 64 bit block ciphers while NESSIE selected none, but CRYPTREC was obliged by its terms of reference to take into account existing standards and practices, while NESSIE was not. Similar differences in terms of reference account for CRYPTREC recommending at least one stream cipher, RC4, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panama (cipher)
Panama is a cryptographic primitive which can be used both as a hash function and a stream cipher, but its hash function mode of operation has been broken and is not suitable for cryptographic use. Based on StepRightUp, it was designed by Joan Daemen and Craig Clapp and presented in the paper ''Fast Hashing and Stream Encryption with PANAMA'' on the Fast Software Encryption (FSE) conference 1998. The cipher has influenced several other designs, for example MUGI and SHA-3.http://csrc.nist.gov/groups/ST/hash/sha-3/documents/Keccak-slides-at-NIST.pdf On slide 5, it states the "starting point: fixing Panama" The primitive can be used both as a hash function and a stream cipher. The stream cipher uses a 256-bit key and the performance of the cipher is very good reaching 2 cycles per byte. Hash function As a hash function, collisions have been shown by Vincent Rijmen et al. in the paper ''Producing Collisions for PANAMA'' presented at FSE 2001. The attack shows a computational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panama (cryptography)
Panama is a cryptographic primitive which can be used both as a hash function and a stream cipher, but its hash function mode of operation has been broken and is not suitable for cryptographic use. Based on StepRightUp, it was designed by Joan Daemen and Craig Clapp and presented in the paper ''Fast Hashing and Stream Encryption with PANAMA'' on the Fast Software Encryption (FSE) conference 1998. The cipher has influenced several other designs, for example MUGI and SHA-3.http://csrc.nist.gov/groups/ST/hash/sha-3/documents/Keccak-slides-at-NIST.pdf On slide 5, it states the "starting point: fixing Panama" The primitive can be used both as a hash function and a stream cipher. The stream cipher uses a 256-bit key and the performance of the cipher is very good reaching 2 cycles per byte. Hash function As a hash function, collisions have been shown by Vincent Rijmen et al. in the paper ''Producing Collisions for PANAMA'' presented at FSE 2001. The attack shows a computational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MDS Matrix
An MDS matrix (maximum distance separable) is a matrix representing a function with certain diffusion properties that have useful applications in cryptography. Technically, an m \times n matrix A over a finite field K is an MDS matrix if it is the transformation matrix of a linear transformation f(x) = Ax from K^n to K^m such that no two different (m + n)-tuples of the form (x, f(x)) coincide in n or more components. Equivalently, the set of all (m + n)-tuples (x, f(x)) is an MDS code, i.e., a linear code that reaches the Singleton bound. Let \tilde A = \begin \mathrm_n \\ \hline \mathrm \end be the matrix obtained by joining the identity matrix \mathrm_n to A. Then a necessary and sufficient condition for a matrix A to be MDS is that every possible n \times n submatrix obtained by removing m rows from \tilde A is non-singular. This is also equivalent to the following: all the sub-determinants of the matrix A are non-zero. Then a binary matrix A (namely over the field with two el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key (cryptography)
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key’s security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Initialization Vector
In cryptography, an initialization vector (IV) or starting variable (SV) is an input to a cryptographic primitive being used to provide the initial state. The IV is typically required to be random or pseudorandom, but sometimes an IV only needs to be unpredictable or unique. Randomization is crucial for some encryption schemes to achieve semantic security, a property whereby repeated usage of the scheme under the same key does not allow an attacker to infer relationships between (potentially similar) segments of the encrypted message. For block ciphers, the use of an IV is described by the modes of operation. Some cryptographic primitives require the IV only to be non-repeating, and the required randomness is derived internally. In this case, the IV is commonly called a nonce (a number used only once), and the primitives (e.g. CBC) are considered ''stateful'' rather than ''randomized''. This is because an IV need not be explicitly forwarded to a recipient but may be derived from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-box
In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Shannon's property of confusion. Mathematically, an S-box is a vectorial Boolean function. In general, an S-box takes some number of input bits, ''m'', and transforms them into some number of output bits, ''n'', where ''n'' is not necessarily equal to ''m''. An ''m''×''n'' S-box can be implemented as a lookup table with 2''m'' words of ''n'' bits each. Fixed tables are normally used, as in the Data Encryption Standard (DES), but in some ciphers the tables are generated dynamically from the key (e.g. the Blowfish and the Twofish encryption algorithms). Example One good example of a fixed table is the S-box from DES (S5), mapping 6-bit input into a 4-bit output: Given a 6-bit input, the 4-bit output is found by selecting the row using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Encryption Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant of the Rijndael block cipher developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the AES selection process. Rijndael is a family of ciphers with different key and block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits. AES has been adopted by the U.S. government. It supersedes the Data Encryption Standard (DES), which was published in 1977. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data. In the United States, AES was announced by the NIST as U.S. FIPS PUB 197 (FIPS 197) on Nov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorandom Number Generator
A pseudorandom number generator (PRNG), also known as a deterministic random bit generator (DRBG), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random numbers. The PRNG-generated sequence is not truly random, because it is completely determined by an initial value, called the PRNG's ''seed'' (which may include truly random values). Although sequences that are closer to truly random can be generated using hardware random number generators, ''pseudorandom number generators'' are important in practice for their speed in number generation and their reproducibility. PRNGs are central in applications such as simulations (e.g. for the Monte Carlo method), electronic games (e.g. for procedural generation), and cryptography. Cryptographic applications require the output not to be predictable from earlier outputs, and more elaborate algorithms, which do not inherit the linearity of simpler PRNGs, are needed. Good statis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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