1. SHA1 (Secure Hash Algorithm 1) :
SHA1 is a cryptographic hash function which is designed by United States National Security Agency. It takes an input and produces a 160 bits hash value. Further the output produced by this function is converted into a 40 digits long hexadecimal number. It is a U.S. Federal Information Processing Standard. It was first published in 1995. It is successor to SH0 published in 1993.
Data : Geeksforgeeks SHA1 : bc7623b7a94ed3d8feaffaf7580df3eca4f5f5ca
2. SHA2 (Secure Hash Algorithm 2) :
SHA1 is also a cryptographic hash function which is designed by United States National Security Agency. It is constructed using the Merkle-Damgard structure from a one-way compression function. The compression function used is constructed using the Davies-Meyer structure from a classified block cipher. It was first published in 2001. It is successor to SH1.
Data : Geeksforgeeks SHA2(256) : 86d755349c6b9f95f365c6ffe7734f25bf2b00cabe8c6bc5f2b8b746c1aac332
Difference between SHA1 and SHA2 :
|It is a cryptographic hash function designed by U.S National Security Agency to replace SH0.||It is a cryptographic hash function designed by U.S National Security Agency to replace SH1.|
|It was published in 1995.||While it was published in 2001.|
|It produces 160 bits hash value.||It produces 224, 256, 384 or 512 bits hash value.|
|It is successor to SH0 and predecessor to SH2.||It is successor to SH1 and predecessor to SH3.|
|It is less secure.||While it is more secure.|
|Its structure is based on Merkle–Damgard construction.||Its structure is based on Merkle–Damgard structure with Davies–Meyer compression function.|
|SHA1 certificates are not reliable.||SHA2 has more improved certificates.|
|It generates smaller hash.||While it generates larger hash.|
|Hash generated by SHA1 is weak.||While hash generated by SHA2 is strong.|
|It is not widely used now-a-days.||While it is used widely.|
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