We used VeryPDF Security and Signature (Shell & COM & SDK) to insert password for system generated PDF file. However, we are unable to use Apple iPhone to open the password protected PDF, the page is blank after entering the password.
Able to advise?
Attached is the sample PDF that we are unable to open using iPhone native email app. A blank page is displayed after the password has been entered.
You may test it using the attached file, with password as "123".
We have checked this PDF file, this PDF file has protected by 256bit AES algorithm, I guess iPhone email app doesn't support 256bit AES protection yet, you may use 128bit AES or 128bit RC4 encryption method to try again.
You can use following command lines to protect your PDF files with rc4, AES128, AES256 encryption methods,
pdfsecure.exe -openpwd 123 -ownerpwd 456 -perm 0 -keylen 128 -stringcrypt AES256 -streamcrypt AES256 -forceencrypt -linearize readme.pdf _readme_out_aes256.pdf
pdfsecure.exe -openpwd 123 -ownerpwd 456 -perm 0 -stringcrypt AES128 -streamcrypt AES128 readme.pdf _readme_out_aes128.pdf
pdfsecure.exe -openpwd 123 -ownerpwd 456 -perm 0 -keylen 128 -stringcrypt rc4 -streamcrypt rc4 -forceencrypt -linearize readme.pdf _readme_out_rc4.pdf
btw, I just tried to open the PDF files which protected by AES128 and rc4 encryption methods, I could view these encrypted PDF files without any problem, so you may use AES128 or rc4 to instead of AES256 for the PDF encryption, AES256 is a very newer encryption method, some iPhone applications don't support AES256 yet.