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The following tables compare general and technical information for a number of cryptographic hash functions. See the individual functions' articles for further information. This article is not all-inclusive or necessarily up-to-date. An overview of hash function security/cryptanalysis can be found at hash function security summary.
Download as PDF; Printable version; ... move to sidebar hide. Comparison of SHA functions . Algorithm and variant Output size (bits) ... SHA-3: SHA3-224 SHA3-256 SHA3-384
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 also truncated versions of each standard, known as SHA-224, SHA-384, SHA-512/224 and SHA-512/256. These were also designed by the NSA.
The block transformation f, which is Keccak-f[1600] for SHA-3, is a permutation that uses XOR, AND and NOT operations, and is designed for easy implementation in both software and hardware. It is defined for any power-of-two word size, w = 2 ℓ bits. The main SHA-3 submission uses 64-bit words, ℓ = 6.
In Excel and Word 95 and prior editions a weak protection algorithm is used that converts a password to a 16-bit verifier and a 16-byte XOR obfuscation array [1] key. [4] Hacking software is now readily available to find a 16-byte key and decrypt the password-protected document. [5] Office 97, 2000, XP and 2003 use RC4 with 40 bits. [4]
One-way hash function, sometimes also called as one-way compression function—compute a reduced hash value for a message (e.g., SHA-256) Symmetric key cryptography—compute a ciphertext decodable with the same key used to encode (e.g., AES) Public-key cryptography—compute a ciphertext decodable with a different key used to encode (e.g., RSA)
For example, SHA-256 operates on 512-bit blocks. The size of the output of HMAC is the same as that of the underlying hash function (e.g., 256 and 512 bits in the case of SHA-256 and SHA3-512, respectively), although it can be truncated if desired. HMAC does not encrypt the message.
More generally, k-independent hashing functions provide a secure message authentication code as long as the key is used less than k times for k-ways independent hashing functions. Message authentication codes and data origin authentication have been also discussed in the framework of quantum cryptography.