LSM Crypt Cookie: Crypt and decrypt data stored in cookies

This is a simple class that can store encrypted values in cookies using a secret key.

The class can generate an encrypted version of a text value using a secret key and store it in a cookie.

Whenever it is necessary to recover the original value, the class can decrypt the value stored in the cookie using the same encryption key.

This way the users may not see the values stored in the cookies unless they know the secret key.