Your desired feature is already implemented - didn't you see the keys?
Code:
UseSecurity = 1;
UseStrongEncryption = 1;
DisallowAnnotation = 1;
DisallowCopy = 1;
DisallowModification = 1;
DisallowPrinting = 1;
OwnerPassword = <040b7479 70656473 74726561 6d8103e8 84014084 8484084e 53537472 696e6701 8484084e 534f626a 65637400 8584012b 04626c61 6886>;
UserPassword = <040b7479 70656473 74726561 6d8103e8 84014084 8484084e 53537472 696e6701 8484084e 534f626a 65637400 8584012b 03626f62 86>;
What you need to do is set up the security options, and THEN save your pPref job options file into your watched folder.