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How to open SFPDF files?

Natalia Yashenkova
Natalia Yashenkova
Head of Marketing and PR at StarForce Technologies.

Natalia Yashenkova has more than 15 years experience in software development and information security. Before StarForce Technologies she worked at Netris and Vimcom Optic.

14 Jul 2015

Files with .SFPDF extension can be opened with a special viewer program - StarForce Reader. Actually the name of the expansion comes from the words StarForce and PDF: SF + PDF. This viewer can open both: SFPDF and usual PDF files.

Download StarForce Reader


SFPDF files are used when it is necessary to protect the content against unauthorized access, copying and sharing. It is a tool for copyright protection.

How to open SFPDF emails

If a SFPDF file is sent with the help of SFLetter.com, a secure email service, it is enough to download and launch StarForce Reader. Every email and attached file has a license that gives the right to open a SFPDF document. However, keep in mind that the protected files can only be opened on one device. After opening the sender receives information about the time of opening and the recipient's IP address. The sender will also be informed if there are attempts to open the protected documents on other devices (time and IP addresses).

SFPDF eDocument opening

If you have downloaded a SFPDF file from the internet or got it some other way then you will not be able to open it without a serial number.

Besides SFLetter.com there is another internet service to create SFPDF files. It is SFContent.com, a DRM system to manage access to PDF files. A publisher (this way we call a person who owns documents/content) generates serial numbers which give the right to view the documents. A serial number consists of English letters and numbers and it could include different limitations. For example a serial number can have an expiry date or geographical restrictions. Also it permits or forbids printing of the documents.

How to find the publisher of a SFPDF file to get a serial number?

A publisher leaves contact information in the tab “Where to buy?”

Is it safe to download and use SFPDF viewer?

The program is designed by Protection Technology, Ltd (the legal name of StarForce). In order to be sure that you are downloading the correct viewer, look at what sites the links lead. They should lead on our official websites: SFContent.com or SFLetter.com.

The viewer needs to have an internet connection to interact with StarForce activation server.  At the activation the viewer sends software and hardware parameters of the computer as a hash sum. It allows to identify the user’s device and to open protected documents only on it.

No other information is sent to StarForce servers.

StarForce Reader has much in common with Adobe Reader. They both can open PDF files. But only StarForce Reader can open SFPDF. 

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