Introduction Here in this article we are discussing about Cryptographic HMACSHA1 one way algorithm. Its feature is Encryption. It is only used for Encryption not used for decryption. It encrypts Text with the help of a Public key. Firstly you enter Text in the TextBox that you want to encrypt and then enter Public key known to everyone and press Text After Encryption Button you will get Encrypted Text. The implementation of example needs three TextBox and one Button control. Getting Started