Search results
Results From The WOW.Com Content Network
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.
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.
The following tables compare general and technical information for a number of cryptographic hash functions. See the individual functions' articles for further information.
TLS 1.0 (deprecated) TLS 1.1 (deprecated) TLS 1.2 TLS 1.3 EV [n 3] [1] SHA-2 [2] ECDSA [3] BEAST [n 4] CRIME [n 5] POODLE (SSLv3) [n 6] RC4 [n 7] FREAK [4] [5] Logjam Google Chrome (Chrome for Android) [n 8] [n 9] 1–9 Windows (10+) macOS (11+) Linux Android (8.0+) iOS (14+) ChromeOS: Disabled by default Yes Yes No No No Yes (only desktop ...
SHA-2 basically consists of two hash algorithms: SHA-256 and SHA-512. SHA-224 is a variant of SHA-256 with different starting values and truncated output. SHA-384 and the lesser-known SHA-512/224 and SHA-512/256 are all variants of SHA-512. SHA-512 is more secure than SHA-256 and is commonly faster than SHA-256 on 64-bit machines such as AMD64.
SHA-2 available in 224, 256, 384, and 512-bit variants; HMAC keyed hash; PBKDF2 Key derivation function (RFC 2898) Digital signature standards.
Generally, the basic security of cryptographic hash functions can be seen from different angles: pre-image resistance, second pre-image resistance, collision resistance, and pseudo-randomness. Pre-image resistance: given a hash h, it should be hard to find any message m such that h = hash(m). This concept is related to that of the one-way function.
Even if a given hash function becomes insecure, it is sufficient to replace it by a different, secure one to obtain a secure instantiation of the hash-based signature scheme under consideration. Some hash-based signature schemes (such as XMSS with pseudorandom key generation) are forward secure, meaning that previous signatures remain valid if ...