Encrypted PDF Generation Results in Empty Document on iPhone
Environment
| Version | Product | Author |
|---|---|---|
| 2025.3.806 | RadPdfProcessing | Desislava Yordanova |
Problem
When generating and encrypting a PDF using Telerik Document Processing, the file appears blank when opened on iPhone devices. However, the same PDF opens correctly on other platforms, including the mobile version of Adobe Acrobat on iPhone.
Description
iOS viewers are sensitive to PDF structure and metadata. Many mobile PDF viewers, including those on iOS, expect linearized PDFs for optimal compatibility, especially when encryption is applied. Non-linearized encrypted PDFs may fail to render properly or show as empty. The AES256 encryption used by Telerik PdfProcessing is broadly compatible, but some viewers require specific encryption flags or additional metadata that may not be present in the generated PDF.
Solution
If you intend to display the generated PDF documents on Apple devices, make sure that you are encrypting the document with the AES128 algorithm.