I am developing an Encryption/Decryption Utility using Adobe AIR. I have chosen the AES algorithm and currently use the
as3crypto library for this. My query is in what practical ways can I detect if the password provided at the time of decryption valid or not.
As of now I thought of encrypting a constant string with the password and storing the encrypted string in the header of my encrypted file. For decryption, I can check if the correct password is provided by decrypting this string.
This is a temporary work around as storing a ciphertext of a known plaintext (The string is hard coded as a constant inside my application) is not a proper way as I know.
Since I don't have much experience, I am looking for a proper and safe way to accomplish this. My application will be a standalone desktop application without a server.