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Keccak
SHA-3 (Secure Hash Algorithm 3) is the latest member of the Secure Hash Algorithm family of standards, released by NIST on August 5, 2015. Although part of the same series of standards, SHA-3 is internally different from the MD5-like structure of SHA-1 and SHA-2. SHA-3 is a subset of the broader cryptographic primitive family Keccak ( or ), designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche, building upon RadioGatún. Keccak's authors have proposed additional uses for the function, not (yet) standardized by NIST, including a stream cipher, an authenticated encryption system, a "tree" hashing scheme for faster hashing on certain architectures, and AEAD ciphers Keyak and Ketje. Keccak is based on a novel approach called sponge construction. Sponge construction is based on a wide random function or random permutation, and allows inputting ("absorbing" in sponge terminology) any amount of data, and outputting ("squeezing") any amount of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RadioGatún
RadioGatún is a Cryptographic hash function, cryptographic hash primitive created by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche. It was first publicly presented at the NIST Second Cryptographic Hash Workshop, held in Santa Barbara, California, on August 24–25, 2006, as part of the NIST hash function competition. The same team that developed RadioGatún went on to make considerable revisions to this cryptographic primitive, leading to the Keccak SHA-3 algorithm. RadioGatún is a family of 64 different hash functions, distinguished by a single parameter, the word width in bits (''w''), adjustable between 1 and 64. The only word sizes with official test vectors are the 32-bit and 64-bit variants of RadioGatún. The algorithm uses 58 words, each using ''w'' bits, to store its internal state, so the 32-bit version needs 232 bytes to store its state (since each word needs 32 bits or four bytes, and 58 multiplied by four is 232) and the 64-bit version 464 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NIST Hash Function Competition
The NIST hash function competition was an open competition held by the US National Institute of Standards and Technology (NIST) to develop a new hash function called SHA-3 to complement the older SHA-1 and SHA-2. The competition was formally announced in the ''Federal Register'' on November 2, 2007. "NIST is initiating an effort to develop one or more additional hash algorithms through a public competition, similar to the development process for the Advanced Encryption Standard (AES)." The competition ended on October 2, 2012 when NIST announced that Keccak would be the new SHA-3 hash algorithm. The winning hash function has been published as NIST FIPS 202 the "SHA-3 Standard", to complement FIPS 180-4, the '' Secure Hash Standard''. The NIST competition has inspired other competitions such as the Password Hashing Competition. Process Submissions were due October 31, 2008 and the list of candidates accepted for the first round was published on December 9, 2008. NIST held a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA-0
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. Since 2005, SHA-1 has not been considered secure against well-funded opponents; as of 2010 many organizations have recommended its replacement. NIST formally deprecated use of SHA-1 in 2011 and disallowed its use for digital signatures in 2013, and declared that it should be phased out by 2030. , chosen-prefix attacks against SHA-1 are practical. As such, it is recommended to remove SHA-1 from products as soon as possible and instead use SHA-2 or SHA-3. Replacing SHA-1 is urgent where it is used for digital signatures. All major web browser vendors ceased acceptance of SHA-1 SSL certificates in 2017. In Februa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA-1
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20- byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. Since 2005, SHA-1 has not been considered secure against well-funded opponents; as of 2010 many organizations have recommended its replacement. NIST formally deprecated use of SHA-1 in 2011 and disallowed its use for digital signatures in 2013, and declared that it should be phased out by 2030. , chosen-prefix attacks against SHA-1 are practical. As such, it is recommended to remove SHA-1 from products as soon as possible and instead use SHA-2 or SHA-3. Replacing SHA-1 is urgent where it is used for digital signatures. All major web browser vendors ceased acceptance of SHA-1 SSL certificates in 2017. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Domain
The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable. Because those rights have expired, anyone can legally use or reference those works without permission. As examples, the works of William Shakespeare, Ludwig van Beethoven, Leonardo da Vinci and Georges Méliès are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by a country's copyright laws, and are therefore in the public domain; for example, in the United States, items excluded from copyright include the formulae of Newtonian physics, cooking recipes,Copyright Protection No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilles Van Assche
Gilles Van Assche is a Belgian cryptographer who co-designed the Keccak cryptographic hash, which was selected as the new SHA-3 hash by NIST in October 2012. The SHA-3 standard was released by NIST on August 5, 2015. In 1998 Van Assche graduated from Université Libre de Bruxelles (ULB) with a Physics Engineer degree. He then went to work for STMicroelectronics while also working on his PhD thesis at the Center for Quantum Information and Communication at the ULB. His PhD thesis was directed by Pr. Nicolas Cerf where he researched quantum key distribution (QKD) and related classical information theory problems such as secret-key distillation, reconciliation and privacy amplification. His thesis was later expanded into a book, "Quantum Cryptography and Secret-Key Distillation" published by Cambridge University Press on 29 June 2006. Along with Joan Daemen and Michaël Peeters he designed the NOEKEON family of block ciphers which were submitted to the NESSIE project in Septemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge Function
In cryptography, a sponge function or sponge construction is any of a class of algorithms with finite internal state that take an input bit stream of any length and produce an output bit stream of any desired length. Sponge functions have both theoretical and practical uses. They can be used to model or implement many cryptographic primitives, including cryptographic hashes, message authentication codes, mask generation functions, stream ciphers, pseudo-random number generators, and authenticated encryption. Construction A sponge function is built from three components: * a state memory, ''S'', containing ''b'' bits, * a function f: \^b \rightarrow \^b * a padding function ''P'' ''S'' is divided into two sections: one of size ''r'' (the bitrate) and the remaining part of size ''c'' (the capacity). These sections are denoted ''R'' and ''C'' respectively. ''f'' produces a pseudorandom permutation of the 2^b states from ''S''. ''P'' appends enough bits to the input string so t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Implementation
In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation often accompanies a technical standard, and demonstrates what should be considered the "correct" behavior of any other implementation of it. Characteristics and examples Reference implementations of algorithms, for instance cryptographic algorithms, are often the result or the input of standardization processes. In this function they are often dedicated to the public domain with their source code as public domain software. Examples are the first CERN's httpd, Serpent cipher, base64 variants, and SHA-3. The Openwall Project maintains a list of several algorithms with their reference source code in the public domain. A reference implementation may or may not be production quality. For example, the Fraunhofer reference implementation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joan Daemen
Joan Daemen (; born 1965) is a Belgian cryptographer who co-designed with Vincent Rijmen the Rijndael cipher, which was selected as the Advanced Encryption Standard (AES) in 2001. More recently, he co-designed the Keccak cryptographic hash, which was selected as the new SHA-3 hash by NIST in October 2012. He has also designed or co-designed the MMB, Square, SHARK, NOEKEON, 3-Way, and BaseKing block ciphers. In 2017 he won the Levchin Prize for Real World Cryptography "for the development of AES and SHA3". He describes his development of encryption algorithms as creating the bricks which are needed to build the secure foundations online. In 1988, Daemen graduated in electro-mechanical engineering at the Katholieke Universiteit Leuven. He subsequently joined the COSIC research group, and has worked on the design and cryptanalysis of block ciphers, stream ciphers and cryptographic hash functions. Daemen completed his PhD in 1995, at which point he worked for a year at Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preimage Attack
In cryptography, a preimage attack on cryptographic hash functions tries to find a message that has a specific hash value. A cryptographic hash function should resist attacks on its preimage (set of possible inputs). In the context of attack, there are two types of preimage resistance: * ''preimage resistance'': for essentially all pre-specified outputs, it is computationally infeasible to find any input that hashes to that output; i.e., given , it is difficult to find an such that . * ''second-preimage resistance'': for a specified input, it is computationally infeasible to find another input which produces the same output; i.e., given , it is difficult to find a second input such that . These can be compared with a collision resistance, in which it is computationally infeasible to find any two distinct inputs , that hash to the same output; i.e., such that . Collision resistance implies second-preimage resistance, but does not guarantee preimage resistance. Conversely, a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Authenticated Encryption
Authenticated Encryption (AE) and Authenticated Encryption with Associated Data (AEAD) are forms of encryption which simultaneously assure the confidentiality and authenticity of data. Programming interface A typical programming interface for an AE implementation provides the following functions: * Encryption ** Input: ''plaintext'', ''key'', and optionally a ''header'' in plaintext that will not be encrypted, but will be covered by authenticity protection. ** Output: ''ciphertext'' and ''authentication tag'' ( message authentication code or MAC). * Decryption ** Input: ''ciphertext'', ''key'', ''authentication tag'', and optionally a ''header'' (if used during the encryption). ** Output: ''plaintext'', or an error if the ''authentication tag'' does not match the supplied ''ciphertext'' or ''header''. The ''header'' part is intended to provide authenticity and integrity protection for networking or storage metadata for which confidentiality is unnecessary, but authenticity is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
