HOW TO DETECT A MODIFIED PDF FILE

Forum|Forum|14 years ago
July 6, 2011
3 respuestas
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Hello everyone,

I re-post this message because I've found a way to detect that a file as been modified . I found that any modification may corrupted the cross reference table & it's easily detect with "bycepdfdata" , a software that shows metadata.... But I don't know if it do detect a file modified with acrobatpro ? Your opinion ?

Thank you

Este tema ha sido cerrado para respuestas.

I

IndianTechSup22230449aipj

Participant

You can use a checksum by right click and then crc sha, its not a guarante, but if its the same its probably the same

370H55V

Inspiring

As I understand it, if you modify (edit) a PDF with Acrobat Pro, it will create a new reference table on save that coincides with the changes made. At that point a new "created" date is applied.

If you don't want anyone to modify your PDFs, why not just lock and password protect them?

MichaelKazlow

Legend

There is no sure proof way to determine if a generic pdf file is modified. If you go to the document properties (control or command d), if the proper metadata is available, it will list the creation date and time and modified date and time. This can help you determine if a pdf file has been modified since creation. However, it is not foolproof. This metadata is not secured. The easiest way to detect if a file has been modified to to digitally sign the document. Reader and Acrobat will report if the document has been changed since it was signed.