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Secure Hash Algorithm (Sha-1) - VPN Tutorial

 

 

The purpose of message integrity algorithms, such as Secure Hash Algorithm (Sha-1), ensures data has not been changed in transit. They use one way hash functions to determine if data has been changed.

Sha-1, which is also known as HMAC-Sha-1 is a strong cryptographic hashing algorithm, stronger than another popular algorithm known as Message Digest 5 (MD5). Sha-1 is used to provide data integrity (to guarantee data has not been altered in transit) and authentication (to guarantee data came from the source it was supposed to come from). Sha was produced to be used with the digital signature standard.

Sha-1 uses a 160-bit encryption key. It is cryptographically stronger and recommended when security needs are higher.

Cryptology specialists did announce a possible small mathematical weakness in Sha-1 and as a result Sha-2 was made available. Sha-2 is actually a group of algorithms, which consist of Sha-256, Sha-384 and Sha-512. However Sha-1 has proven to be a strong hashing algorithm and there are no records of it being hacked so far.

Other integrity algorithms include MD2, MD5, MD6, Haval and Tiger.

Further Reading

Wikipedia's guide to Sha-1