Hi,
I wonder how acrobat handles a password that contains unicode characters when generating an encryption key. That is, what byte representation (i.e. encoding of the password string) is used, before padding the password in Algorithm 3.2 (PDF Reference 1.7)?
In another thread (http://forums.adobe.com/message/2235717#2235717) it was stated that only characters that fall into the PDFDocEncoding (basically ISO-8859-1) are allowed. However, I found that in Acrobat I can enter non ISO-8859-1 characters for my password (and successfully reopen the file with Acrobat Reader on another machine using this password). However I cannot open the file with other PDF-readers (evince, PDF-XChange Viewer) that just work fine with non-unicode passwords.
Is there a document that explains these details? Are there any differences between the different PDF versions?
Thanks,
Michael