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SHA-3
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 data ... [...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 co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA-2
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression function itself built using the Davies–Meyer structure from a specialized block cipher. SHA-2 includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with digests (hash values) that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256. SHA-256 and SHA-512 are novel hash functions computed with eight 32-bit and 64-bit words, respectively. They use different shift amounts and additive constants, but their structures are otherwise virtually identical, differing only in the number of rounds. SHA-224 and SHA-384 are truncated versions of SHA-256 and SHA-512 respectively, computed with different initial values. SHA-512/224 and SHA-512/256 are also trunc ... [...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 S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Hash Algorithm
The Secure Hash Algorithms are a family of cryptographic hash functions published by the National Institute of Standards and Technology (NIST) as a U.S. Federal Information Processing Standard (FIPS), including: * SHA-0: A retronym applied to the original version of the 160-bit hash function published in 1993 under the name "SHA". It was withdrawn shortly after publication due to an undisclosed "significant flaw" and replaced by the slightly revised version SHA-1. *SHA-1: A 160-bit hash function which resembles the earlier MD5 algorithm. This was designed by the National Security Agency (NSA) to be part of the Digital Signature Algorithm. Cryptographic weaknesses were discovered in SHA-1, and the standard was no longer approved for most cryptographic uses after 2010. *SHA-2: A family of two similar hash functions, with different block sizes, known as ''SHA-256'' and ''SHA-512''. They differ in the word size; SHA-256 uses 32-bit words where SHA-512 uses 64-bit words. There are als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RadioGatún
RadioGatún is a 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 bytes (each word using eig ... [...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 Febr ... [...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 F ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Security Strength
In cryptography, security level is a measure of the strength that a cryptographic primitive — such as a cipher or hash function — achieves. Security level is usually expressed as a number of " bits of security" (also security strength), where ''n''-bit security means that the attacker would have to perform 2''n'' operations to break it, but other methods have been proposed that more closely model the costs for an attacker. This allows for convenient comparison between algorithms and is useful when combining multiple primitives in a hybrid cryptosystem, so there is no clear weakest link. For example, AES-128 ( key size 128 bits) is designed to offer a 128-bit security level, which is considered roughly equivalent to a RSA using 3072-bit key. In this context, security claim or target security level is the security level that a primitive was initially designed to achieve, although "security level" is also sometimes used in those contexts. When attacks are found that ha ... [...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 ... [...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 of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycles Per Byte
Encryption software is software that uses cryptography to prevent unauthorized access to digital information. Cryptography is used to protect digital information on computers as well as the digital information that is sent to other computers over the Internet. Classification There are many software products which provide encryption. Software encryption uses a cipher to obscure the content into ciphertext. One way to classify this type of software is the type of cipher used. Ciphers can be divided into two categories: public key ciphers (also known as asymmetric ciphers), and symmetric key ciphers. Encryption software can be based on either public key or symmetric key encryption. Another way to classify software encryption is to categorize its purpose. Using this approach, software encryption may be classified into software which encrypts " data in transit" and software which encrypts " data at rest". Data in transit generally uses public key ciphers, and data at rest generally use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
