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PDF Concatenate to retain the Security


After the merging multiple PDF's the output.pdf is not retaining the security settings of source pdf. Can you please help me on this.

Please let me know if you need any clarification on this.

//create a array to hold file names

string[] files = Directory.GetFiles(@"C:\temp\PDF\LIFE");

PdfFileEditor pdfEditor = new PdfFileEditor();

//first svae the existing strategy

FileProcessingStrategy strategy = Settings.Strategy;

//set new strategy to OptimizeMemoryUsage

Settings.Strategy = FileProcessingStrategy.AutoDetect;


//revert back to the previous strategy

Settings.Strategy = strategy;

Hi Muthiah,

Please try to use our latest version, published yesterday. If it doesn’t resolve your issue then please share the input PDF files with us, so we could investigate this issue at our end.

We’re sorry for the inconvenience.

Thank you for your response. It is retaining the document privilege but it is not retaining the Security Method. The source pdf Security Method is Password Security but after the PDF merge the output pdf secuirty method changing to No Secuirty.

Can you please help me resolving this issue.



Hi Muthiah,

I'm sorry to inform you that Concatenate method can't retain the password enabled security and encryption. You need to encrypt the output file explicity once it is concatenated. You can use EncryptFile method to do that. Please see this help topic for more details.

I hope this helps. If you have any further questions, please do let us know.