Q13414952
Sign in to saveIn cryptography, SHA-1 (Secure Hash Algorithm 1) is a hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. The algorithm has been cryptographically broken but is still widely used.
Key facts
- Encryption method.cryptanalysis
- A 2011 attack by Marc Stevens can produce hash collisions with a complexity between 260.3 and 265.3 operations. The first public collision was published on 23 February 2017. SHA-1 is prone to length extension attacks.
- Encryption method.name
- SHA-1
- Encryption method.designers
- National Security Agency
- Encryption method.publish date
- 1993 (SHA-0),1995 (SHA-1)
- Encryption method.series
- (SHA-0), SHA-1, SHA-2, SHA-3
- Encryption method.certification
- FIPS PUB 180-4, CRYPTREC (Monitored)
- Encryption method.digest size
- 160 bits
- Encryption method.block size
- 512 bits
- Encryption method.structure
- Merkle–Damgård construction
- Encryption method.rounds
- 80
via Wikipedia infobox
Article
21 sectionsContents
- Development
- Applications
- Cryptography
- Data integrity<span class="anchor" id="Data Integrity"></span>
- Cryptanalysis and validation
- SHA-0
- Attacks
- The SHAppening
- SHAttered – first public collision
- Birthday-Near-Collision Attack – first practical chosen-prefix attack
- Official validation
- Examples and pseudocode
- Example hashes
- SHA-1 pseudocode
- Comparison of SHA functions
- Implementations
- Collision countermeasure
- See also
- Notes
- References
- External links
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. The algorithm has been cryptographically broken but is still widely used.
Since 2005, SHA-1 has not been considered secure against well-funded opponents; as of 2010 many organizations have recommended its replacement. NIST formally deprecated use of SHA-1 in 2011 and disallowed its use for digital signatures in 2013, and declared that it should be phased out by 2030. , chosen-prefix attacks against SHA-1 are practical. As such, it is recommended to remove SHA-1 from products as soon as possible and instead use SHA-2 or SHA-3. Replacing SHA-1 is urgent where it is used for digital signatures.