Search results
Results From The WOW.Com Content Network
Nobody has been able to break SHA-1, but the point is the SHA-1, as far as Git is concerned, isn't even a security feature. It's purely a consistency check. The security parts are elsewhere, so a lot of people assume that since Git uses SHA-1 and SHA-1 is used for cryptographically secure stuff, they think that, Okay, it's a huge security feature.
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.
It was withdrawn by the NSA shortly after publication and was superseded by the revised version, published in 1995 in FIPS PUB 180-1 and commonly designated SHA-1. Collisions against the full SHA-1 algorithm can be produced using the shattered attack and the hash function should be considered broken. SHA-1 produces a hash digest of 160 bits (20 ...
HMAC-SHA1 generation. In cryptography, an HMAC (sometimes expanded as either keyed-hash message authentication code or hash-based message authentication code) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key.
MD5 and SHA-1 in particular both have published techniques more efficient than brute force for finding collisions. [3] [4] However, some hash functions have a proof that finding collisions is at least as difficult as some hard mathematical problem (such as integer factorization or discrete logarithm). Those functions are called provably secure. [2]
shasum is a Perl program to calculate any of SHA-1, 224, 256, 384, 512 hashes. [7] It is part of the ActivePerl distribution. sha3sum is a similarly named program that calculates SHA-3, HAKE, RawSHAKE, and Keccak functions. [8] The <hash>sum naming convention is also used by the BLAKE team with b2sum and b3sum, by the program tthsum, and many ...
The widely used SHA-1 and SHA-2 hash functions were designed by NSA. SHA-1 is a slight modification of the weaker SHA-0 algorithm, also designed by NSA in 1993. This small modification was suggested by the NSA two years later, with no justification other than the fact that it provides additional security.
However, most common implementations use a fixed bit-size (generally 64 or 128 bits in modern algorithms) at a fixed position at the end of the last block for inserting the message length value (see SHA-1 pseudocode). Further improvement can be made by inserting the length value in the last block if there is enough space.