What is Audio Encryption?

What does the encryption key means?

• i am reading a papers about data encryption ; but can not understand what is meant by the encryption key. it is mentioned that "For a given plain text message, encrypted version will differ for different key sequences". so how determine the encruption key and for a givien security algorithim will it alwys uses the same encryption key ?

• Answer:

  The encryption key is provided by the user, and thus varies per encryption "act". It is a string that is used as input to modify the to-be-encrypted data. So, knowing the key, and the encryption method (i.e. algorithm) you can decrypt something. In the simplest terms, suppose you wanted to hide your SSN. And the encryption method is to subtract some number (call this the key) from it. So then, you could write the RESULT of that on a piece of paper, but without people knowing the method and the key, they don't know how to get back to the original. I may use the exact same encryption method, but I may supply a different encryption key (i.e. a different number to be subtracted from my SSN). Encryption methods are shared by many people, but because each user has the potential to provide a totally different encryption key, cracking them is very difficult.