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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.
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. [3] [4] 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.
Typically, a unique salt is randomly generated for each password. The salt and the password (or its version after key stretching) are concatenated and fed to a cryptographic hash function, and the output hash value is then stored with the salt in a database. The salt does not need to be encrypted, because knowing the salt would not help the ...
To give her additional assurance that there is no man-in-the-middle attack, Bob creates a proof that he knows the password (or a salted hash thereof), and includes his certificate into this proof. This inclusion is called channel binding, as the lower encryption channel is 'bound' to the higher application channel.
The basic question is the meaning of hard.There are two approaches to answer this question. First is the intuitive/practical approach: "hard means that it is almost certainly beyond the reach of any adversary who must be prevented from breaking the system for as long as the security of the system is deemed important."
The encryption process consists of updating the state with four round functions over 10 rounds. The four round functions are SubBytes (SB), ShiftColumns (SC), MixRows (MR) and AddRoundKey (AK). During each round the new state is computed as S = A K ∘ M R ∘ S C ∘ S B ( S ) {\displaystyle S=AK\circ MR\circ SC\circ SB(S)} .
It is like a salt in that it is a randomized value that is added to a password hash, and it is similar to an encryption key in that it should be kept secret. A pepper performs a comparable role to a salt or an encryption key , but while a salt is not secret (merely unique) and can be stored alongside the hashed output, a pepper is secret and ...
In cryptography, the Merkle–Damgård construction or Merkle–Damgård hash function is a method of building collision-resistant cryptographic hash functions from collision-resistant one-way compression functions. [1]: 145 This construction was used in the design of many popular hash algorithms such as MD5, SHA-1, and SHA-2.