FINAL by: OSAC Program Office; Version 2, January 13, 2020 1

OSAC RESEARCH NEEDS ASSESSMENT FORM

Title of research need: Authentication of PDF Documents

Describe

the need:

Image authentication is required to determine if an image/photographic file is what it 

purports to be, whether it has been altered since its creation, and if it provides a fair and 

accurate representation of information depicting actual objects, scenes, and/or events. 

Many files are converted to the PDF file format while the original digital photographs, 

scans, or other documents are lost or destroyed. Digital photographs contain considerable 

metadata that assists in authentication, but once the file is embedded into a PDF such 

metadata may no longer be available, while other metadata may be created.

Image analysts need a better understanding of the PDF file format structure, what 

metadata it contains, how images can be embedded into them, how to determine the 

native resolutions and file formats of the embedded files, whether the PDF has been 

altered or resaved since its creation, etc.

Keyword(s): Authentication, Analysis, PDF, Questioned Documents, Photographic Analysis

Submitting subcommittee(s): VITAL and Footwear & Tire Date Approved: 06/16/2021

(If SAC review identifies additional subcommittees, add them to the box above.)

Background Information:

1. Does this research need address a gap(s) in a current or planned standard? (ex.: Field identification system 

for on scene opioid detection and confirmation)

VITAL may pursue a standard regarding PDF authentication if we can get the research.

2. Are you aware of any ongoing research that may address this research need that has not yet been published 

(e.g., research presented in conference proceedings, studies that you or a colleague have participated in but 

have yet to be published)?

Yes, I believe that DARPA MediFor and SemaFor have done some work on this in conjunction with Purdue University.

3. Key bibliographic references relating to this research need: (ex.: Toll, L., Standifer, K. M., Massotte, D., eds. 

(2019). Current Topics in Opioid Research. Lausanne: Frontiers Media SA. doi: 10.3389/978-2-88963-180-3)

4. Review the annual operational/research needs published by the National Institute of Justice (NIJ) at 

https://nij.ojp.gov/topics/articles/forensic-science-research-and-development-technology-working-groupoperational#latest? Is your research need identified by NIJ?

No.
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5. In what ways would the research results improve current laboratory capabilities?

It would enable a substantially more complete method for authenticating PDF files.

6. In what ways would the research results improve understanding of the scientific basis for the 

subcommittee(s)?

This would add information of value for authentication, in general, and specifically with PDF documents to Digital 

Evidence, Forensic Documents, and VITAL.

7. In what ways would the research results improve services to the criminal justice system?

Many image-based and text-based documents are converted to PDF. This currently adds difficulty in authenticating 

those files. This research would enable analysts to better determine if a PDF file is what it purports to be.

8. Status assessment (I, II, III, or IV): I

Major gap in 

current 

knowledge

Minor gap in 

current 

knowledge

No or limited

current research is 

being conducted I III

Existing current 

research is being 

conducted II IV

This research need has been identified by one or more subcommittees of OSAC and is being provided as an 

informational resource to the community.