> but why should PDFs have encryption built-in to the file format?
Because very few 'end user' people know how to use en/decryption. So it's much easier to send them a familiar file and say 'enter this password' than to have them searching the web to work out which arguments to pass to openssl. In a command line? What's that?
I received an AES-encrypted file recently but neither gnupg nor openssl could determine what mode and keysettings the sender had used, so it was just a useless lump of data. Very secure though...
Because very few 'end user' people know how to use en/decryption. So it's much easier to send them a familiar file and say 'enter this password' than to have them searching the web to work out which arguments to pass to openssl. In a command line? What's that?
I received an AES-encrypted file recently but neither gnupg nor openssl could determine what mode and keysettings the sender had used, so it was just a useless lump of data. Very secure though...