Develop a PDF failproof and hacking-proof "marking" software to be run on Linux machine

Hello everybody,


I have on my forum a database of files downloadable and uploadable by end users. I need a software application to “mark” every single file we have on our database with a specific and unique encrypted sequence, totally invisible to end user.

This sequence has then to be saved on a database and associated with the file itself. I will later use this information to check, when my users will upload new documents, whether these already are on our database or not.


• The software will run on a Linux machine

• The “mark” has not to affect the user experience in reading the pdf in any way

• I don’t need a DRM application. Files have to be fully open-able with no “expiration” date. I just need to mark each file “invisibly”.

• The software has to operate so that for those who want to hack or circumvent this encryption it is impossible to: 1) delete it with other PDF watermarking/unlocking softwares 2)reverse engineer the algorithm

• The software application has to be built under the “black box” principle: I provide some input, it provides us back with the output. These are the functions that we need 1)Checkfile 2)ProtectFile

1) Input: file_name; file_path

Output: Outcome (Y|N); steg_unique_sequence_found [if any]; duplicate_file_found [if any]; duplicate_file_path [if any];

2) Input: file_name; file_path

Output: Outcome (Y|N); Error [if any]; Outcome_file_path; outcome_file_name; outcome_file_specific sequence; steg_unique_sequence

• Encripted sequence has to be added to every single page

• The software has to be “fail proof” and work on any type of pdf (even protected ones), with pages of any dimension).


• I need the property of the source code of this application.

• I need a ready-to-use software with a proper instruction manual

• I need a developer with previous experience in programming and encryption algorithm

Skills: Linux, PDF, PHP, Python, Software Architecture

See more: use algorithm programming, source linux information, python programming software, python programming pdf, python database programming, proof reading softwares, proof reading application, programming python pdf, php developer pdf, machine proof reading, machine programming, linux programming pdf, want develop property, develop algorithm, black box programming, algorithm encryption, python reverse, python forum, proof reading work, programming php pdf, pdf php programming, need software engineer, software engineer python, python algorithm, marking

About the Employer:
( 30 reviews ) Torino, Italy

Project ID: #4196161

3 freelancers are bidding on average $467 for this job


please check my private message for proposal details.

$350 USD in 2 days
(11 Reviews)

Hello, Thanks for posting the project on Freelancer. We have gone through the requirements and have some queries over it which we have sent on to your PMB. Kindly review the same and answer the queries so t More

$250 USD in 1 day
(7 Reviews)

Hi , I am interested in taking this project. Please check my PMB for more details.

$750 USD in 12 days
(21 Reviews)

Hi, I am familiar with PDF document specification. I think I can provide you an elegant solution for your issue. Cheers.

$400 USD in 7 days
(21 Reviews)