Hello Everyone,
I've noticed something odd when using Acrobat X Pro to output an AES-256 encrypted PDF file for "Acrobat X and higher". The standard encryption dictionary has R as 6 (see below).
77 0 obj <>>>/Filter/Standard/Length 256/O(blahblah))/OE(blahblah)/P -1028/Perms(blahblah)/R 6/StmF/StdCF/StrF/StdCF/U(blahblah))/UE(blahblah)/V 5>> endobj
R = number (Required) A number specifying which revision of the standard security handler should be used to interpret this dictionary...
Does anyone know where a value of "6" is documented/specified? My reference is "PDF Reference sixth edition Version 1.7 November 2006" and "Adobe Supplement to the ISO 32000 BaseVersion: 1.7 ExtensionLevel: 3".
Additionally, I assume R=6 and R=5 have different encryption algorithms as I can't get R=6 steams and strings to decrypt. Can anyone confirm or deny this assumption?
Thanks!
Albert