how to decrypt a string

Question

How to restore the value of a string after using FormsAuthentication.HashPasswordForStoringInConfigFile()

i have a string s1 = "abc" then

FormsAuthentication.HashPasswordForStoringInConfigFile(s1, "SHA1") = A9993E364706816ABA3E25717850C26C9CD0D89D

How can i decrypt "A9993E364706816ABA3E25717850C26C9CD0D89D" back to "abc"??

Answer 1

You Can't, Hash Function are one way functions. this is why it is used for passwords, because that you can't get the password using some reverse function on the hash value.