PDF Mode 10500: RC4 or AES being used?

[SeaWizard]

Hello everyone!



I'm working on a PDF with the following stats (extracted with exiftool v12.80):

Code:

PDF Version: 1.4

Encryption: Standard V2.3 (128-bit)

The generated hash (cropped):

Code:

$pdf$2*3*128*-4*1*16*103f

According to this overview Example Hashes the right mode should be 10500 (PDF 1.4 - 1.6)?

But after some research if found out, that v1.6 introduced AES encryption (reference e.g. here), but prior versions used RC4 in 128bit mode.



So my question would be: is the mode 10500 suitable for both variants?

Because I thought RC4 is much weaker than AES and thus faster to break...

Keep up the good work!
Regards