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Sha-1 Hash Generator
Sha-1 Hash Generator / Sha-1 Hash Encoder Tools
SHA-1 is a cryptographic hash function designed by the United States National Security Agency and published by the United States NIST as a U.S. Federal Information Processing Standard. SHA stands for secure hash algorithm. The four SHA algorithms are structured differently and are distinguished as SHA-0, SHA-1, SHA-2, and SHA-3. SHA-1 is very similar to SHA-0, but corrects an error in the original SHA hash specification that led to significant weaknesses. The SHA-0 algorithm was not adopted by many applications. SHA-2 on the other hand significantly differs from the SHA-1 hash function.
SHA-1 is the most widely used of the existing SHA hash functions, and is employed in several widely used applications and protocols.
In 2005, cryptanalysts found attacks on SHA-1 suggesting that the algorithm might not be secure enough for ongoing use. NIST required many applications in federal agencies to move to SHA-2 after 2010 because of the weakness. Although no successful attacks have yet been reported on SHA-2, they are algorithmically similar to SHA-1. In 2012, following a long-running competition, NIST selected an additional algorithm, Keccak, for standardization as SHA-3
Use of SHA-1 in MS Office password protection
SHA-1 was first used in Microsoft Office 2007. Before a password-protected Word, Excel, and PowerPoint document is opened, 50000 conversions of a password to a 128-bit key occur. It considerably slows down brute-force attack speed and therefore chances to open the password-protected document decline as well. SHA-1 conversions are only used when a password to open document is set since it is the only password type that features document encryption. In Microsoft Office 2010 a number of SHA-1 conversions was doubled and comprises 100000.