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Streebog
Streebog () is a cryptographic hash function defined in the Russian national standard GOST R 34.11-2012 ''Information Technology – Cryptographic Information Security – Hash Function''. It was created to replace an obsolete GOST hash function defined in the old standard GOST R 34.11-94, and as an asymmetric reply to SHA-3 competition by the US National Institute of Standards and Technology. The function is also described in RFC 6986 and one out of hash functions in ISO/IEC 10118-3:2018. Description Streebog operates on 512-bit blocks of the input, using the Merkle–Damgård construction to handle inputs of arbitrary size. The high-level structure of the new hash function resembles the one from GOST R 34.11-94, however, the compression function was changed significantly. The compression function operates in Miyaguchi–Preneel mode and employs a 12-round AES-like cipher with a 512-bit block and 512-bit key. (It uses an 8×8 matrix of bytes rather than AES's 4×4 matrix.) S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOST (hash Function)
The GOST hash function, defined in the standards GOST R 34.11-94 and GOST 34.311-95 is a 256-bit cryptographic hash function. It was initially defined in the Russian national standard GOST R 34.11-94 ''Information Technology – Cryptographic Information Security – Hash Function''. The equivalent standard used by other member-states of the Commonwealth of Independent States, CIS is GOST 34.311-95. This function must not be confused with a different Streebog hash function, which is defined in the new revision of the standard GOST R 34.11-2012. The GOST hash function is based on the GOST (block cipher), GOST block cipher. Algorithm GOST processes a variable-length message into a fixed-length output of 256 bits. The input message is broken up into chunks of 256-bit blocks (eight 32-bit endianness, little endian integers); the message is padding (cryptography), padded by appending as many zeros to it as are required to bring the length of the message up to 256 bits. The remaining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Function Security Summary
This article summarizes publicly known attacks against cryptographic hash functions. Note that not all entries may be up to date. For a summary of other hash function parameters, see comparison of cryptographic hash functions. Table color key Common hash functions Collision resistance Chosen prefix collision attack Preimage resistance Length extension *Vulnerable: MD5, SHA1, SHA256, SHA512 *Not vulnerable: SHA384, SHA-3, BLAKE2 Less-common hash functions Collision resistance Preimage resistance Attacks on hashed passwords Hashes described here are designed for fast computation and have roughly similar speeds. Because most users typically choose short passwords formed in predictable ways, passwords can often be recovered from their hashed value if a fast hash is used. Searches on the order of 100 billion tests per second are possible with high-end graphics processors. Special hashes called key derivation functions have been created to slow brute for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second 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. Second-preimage resistance implies preimage resistance only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collision Attack
In cryptography, a collision attack on a cryptographic hash tries to find two inputs producing the same hash value, i.e. a hash collision. This is in contrast to a preimage attack where a specific target hash value is specified. There are roughly two types of collision attacks: ;Classical collision attack: Find two different messages ''m''1 and ''m''2 such that ''hash''(''m''1) = ''hash''(''m''2). More generally: ;Chosen-prefix collision attack: Given two different prefixes ''p''1 and ''p''2, find two suffixes ''s''1 and ''s''2 such that ''hash''(''p''1 ∥ ''s''1) = ''hash''(''p''2 ∥ ''s''2), where ∥ denotes the concatenation operation. Classical collision attack Much like symmetric-key ciphers are vulnerable to brute force attacks, every cryptographic hash function is inherently vulnerable to collisions using a birthday attack. Due to the birthday problem, these attacks are much faster than a brute force would be. A hash of ''n'' bits can be broken in 2''n''/2 time steps (e ... [...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. Second-preimage resistance implies preimage resistance only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Even though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Quick Brown Fox Jumps Over The Lazy Dog
"The quick brown fox jumps over the lazy dog" is an English-language pangram a sentence (linguistics), sentence that contains all the letters of the alphabet. The phrase is commonly used for Touch typing, touch-typing practice, testing typewriters and computer keyboards, displaying examples of fonts, and other applications involving text where the use of all letters in the alphabet is desired. History The earliest known appearance of the phrase was in ''The Boston Journal''. In an article titled "Current Notes" in the February 9, 1885, edition, the phrase is mentioned as a good practice sentence (linguistics), sentence for writing students: "A favorite copy set by writing teachers for their pupils is the following, because it contains every letter of the alphabet: 'A quick brown fox jumps over the lazy dog. Dozens of other newspapers published the phrase over the next few months, all using the version of the sentence starting with "A" rather than "The". The earliest known use o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avalanche Effect
In cryptography, the avalanche effect is the desirable property of cryptographic algorithms, typically block ciphers and cryptographic hash functions, wherein if an input is changed slightly (for example, flipping a single bit), the output changes significantly (e.g., half the output bits flip). In the case of high-quality block ciphers, such a small change in either the key or the plaintext should cause a drastic change in the ciphertext. The actual term was first used by Horst Feistel, although the concept dates back to at least Shannon's ''diffusion''. If a block cipher or cryptographic hash function does not exhibit the avalanche effect to a significant degree, then it has poor randomization, and thus a cryptanalyst can make predictions about the input, being given only the output. This may be sufficient to partially or completely break the algorithm. Thus, the avalanche effect is a desirable condition from the point of view of the designer of the cryptographic algorithm or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stribog
Stribog is a god in Slavic mythology found in three East Slavic sources, whose cult may also have existed in Poland. The sources do not inform about the functions of the god, but nowadays he is most often interpreted as a wind deity who distributes wealth.' History Stribog appears for the first time in the 12th-century ''Primary Chronicle'' together with other gods for whom Vladimir the Great erected statues: In ''The Tale of Igor's Campaign'', the winds are called ''Stribog's grandsons'': The ''word of John Chrysostom'' also mentions Stribog: Legacy After Christianization, the name was preserved in toponymy: Стрибожь, ''Stribozh in Novgorod Governorate, Стрибоже, ''Strybozhe'' leak, Стрибожская, ''Strybozhskaya'' river in Kiev Voivodeship, Стрибож, ''Strybozh'' village in Zhytomyr Oblast, in Poland '' Strzyboga'' village and the ''Striboc'' (= ''Stribog'') stream near Tczew, attested in the 1282, and possibly Latin name for river ... [...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 Belgium, Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the Advanced Encryption Standard process, AES selection process. Rijndael is a family of ciphers with different key size, key and Block size (cryptography), 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 Federal government of the United States, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Security Service
The Federal Security Service of the Russian Federation СБ, ФСБ России (FSB) is the principal security agency of Russia and the main successor agency to the Soviet Union's KGB; its immediate predecessor was the Federal Counterintelligence Service (FSK), which was reorganized into the FSB in 1995. The three major structural successor components of the former KGB that remain administratively independent of the FSB are the Foreign Intelligence Service (SVR), the Federal Protective Service (FSO), and the Main Directorate of Special Programs of the President of the Russian Federation (GUSP). The primary responsibilities are within the country and include counter-intelligence, internal and border security, counterterrorism, surveillance and investigating some other types of serious crimes and federal law violations. It is headquartered in Lubyanka Square, Moscow's center, in the main building of the former KGB. The director of the FSB is appointed by and direct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miyaguchi–Preneel
In cryptography, a one-way compression function is a function that transforms two fixed-length inputs into a fixed-length output.Handbook of Applied Cryptography by Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone. Fifth Printing (August 2001) page 328. The transformation is "one-way", meaning that it is difficult given a particular output to compute inputs which compress to that output. One-way compression functions are not related to conventional data compression algorithms, which instead can be inverted exactly (lossless compression) or approximately (lossy compression) to the original data. One-way compression functions are for instance used in the Merkle–Damgård construction inside cryptographic hash functions. One-way compression functions are often built from block ciphers. Some methods to turn any normal block cipher into a one-way compression function are Davies–Meyer, Matyas–Meyer–Oseas, Miyaguchi–Preneel (single-block-length compression functions) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
