Introduction - If you have any usage issues, please Google them yourself
SHA1
The SHA1 encryption algorithm specifies a Secure Hash Algorithm (SHA1), which can be used to generate a
condensed representation of a message called a message digest. The SHA1 is required for use with the Digital
Signature Algorithm (DSA) as specified in the Digital Signature Standard (DSS) and whenever a secure hash
algorithm is required. Both the transmitter and intended receiver of a message in computing and verifying a
digital signature uses the SHA1.