Lock PDF Files & Documents

How to lock a PDF from editing, printing, copying – stop sharing & piracy


Lock PDF files regardless of their location:

  • Stop unauthorized access
  • Stop sharing and distribution
  • Strong US Gov strength encryption, DRM and licensing controls

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PDF Protection to lock PDF files & restrict use: lock PDF from editing, copying, printing

How to lock a PDF file with Safeguard PDF Writer

Locking PDFs with Safeguard is more secure than Adobe password protection & simple.  To lock PDF files & stop unauthorized use, choose the DRM controls:

Safeguard automatically protects PDFs from unauthorized sharing:

  • PDF files are locked from being edited or changed (read only).
  • Users cannot copy or save protected PDFs into unprotected files
  • There are no passwords to enter or remove.
  • If a protected PDF is sent to a unauthorized user they can’t open it.
  • PDF documents are automatically locked to machines (authorized devices).
  • You can restrict use to IP and country locations.
  • Stops screen grabbing software from taking screenshots.
  • Remotely revoke PDF files at any time.

locking pdfs

   DID YOU KNOW?

Why you should NOT use PDF passwords

  1. users can share passwords and thus ‘protected’ PDFs with others
  2. passwords are easily removed with PDF password recovery software
  3. Adobe PDF permissions (stop copy, print, editing) can be easily bypassed or removed
  4. once the user has the password, they can unprotect the PDF and do what they like with it

“We have been looking for years to find a software company that would allow us to securely sell our eBooks. Locklizard offers so many options, we are able to fill the needs of all of our customers. We have used other software providers that had promised the security of our eBooks but they never lived up to that promise the way that Locklizard has.

The support we received has been outstanding. They are very responsive to our requests and go the extra mile.

I would recommend Locklizard if you are looking for secure PDFs.”

  Why Safeguard PDF Security is more secure than Adobe Acrobat for Locking PDF documents

  • Strong PDF Security

    Removing Adobe PDF password protection is simple, wheras Safeguard PDF security cannot be easily bypassed.

    With Safeguard:

    • PDFs are only ever decrypted in memory
    • Keys are transparently relayed and locked to authorized devices
    • DRM controls are persistent and cannot be removed
    • OS controls prevent screen grabbing and printing to PDF files and other unprotected document formats

  • Stops unauthorized use

    Stops sharing, copying and pasting, printing, editing and saving.

    Stops screen grabbers and Windows print screen, and prevents printing to file drivers (stops users creating unprotected files such as PDF files or  XPS files).

    Unlike Adobe permissions, Safeguard document controls cannot be removed.  Regardless of how strong the password you use is, Adobe permissions can be removed in seconds.  This can be easily done without using any password removal tools.

  • Non-removable dynamic watermarks

    Dynamic watermarks (user’s name, email, company, date/time, etc.) can be displayed at view/print time.

    You only have to protect the PDF once for all users and unique information is inserted depending on which user has opened the document.

    Unlike Adobe, MS Office, and other software used to add watermarks to PDF files, Safeguard watermarks cannot be easily removed.

  • PDFs are locked to devices and locations

    Restrict PDF files to machines.  PDFs are automatically restricted to machines (authorized devices) so they cannot be shared.  Once a user activates their license they can only view PDF files from that device.

    Restrict PDF files to locations.  PDFs can also be locked to a country, location, a domain, or a range of IP addresses on a user or global basis.  For example, you might only want to allow users to use your protected PDF files from an office location.

  • PDF Expiry & Revocation

    • Set PDF files to expire on a date, after a number of days, a number of opens or prints.
    • Individual user access to the same PDF document can be set to expire at different times.
    • Revoke PDF files instantly regardless of where they are located.

  • Track & Log PDF use

    Track PDF files to see when users viewed and printed your PDF documents.

Safeguard uses US Government strength encryption and digital rights management (DRM) controls to protect PDF documents and control their use.  Lock PDF files from editing, unauthorized sharing and misuse, securely distribute PDF documents, securely share and sell PDFs.

How to lock PDF files to prevent changes & restrict use: prevent editing, copying, printing

  How to Lock a PDF from opening

You can use either passwords or certificates to lock a PDF file from opening but they both have their problems.

A more secure and easier way to prevent a PDF being opened by unauthorized users is to use encryption with licensing controls and transparent key management.  You therefore do not have to worry about key distribution.  This is what Locklizard uses along with device locking to prevent encryption keys (and therefore your documents) from being shared.

  How to Lock a PDF from editing

Most PDF editors enable you to lock a PDF from editing.  However these restrictions can be easily removed.

Locklizard automatically prevents PDF editing when you protect it.  Users cannot edit content or copy/paste it to other applications.  You can also lock PDF forms so that form fields cannot be edited and modified in any way, but the user can still enter text in the fields provided.

  Locking PDFs with Adobe Acrobat

Adobe Acrobat lets you lock or encrypt PDF files with a password so that they are set to view or read only (cannot be edited or printed).

However, the only protection available is the password which can be easily removed using freely available PDF password removal tools.  Once the password is removed the recipient can do what they like with the file.

How to lock PDF from editing with a password:
  1. Open your PDF in Acrobat and press the “Protect” button in the sidebar.
  2. Click “Protect Using Password” in the top bar.
  3. Select “Editing” and enter a secure password.
  4. Save your password protected document.

You can then apply a document open password (Viewing) in the “Advanced options” section of the security header, but that does not prevent users removing the restrictions.  Anyone that has the document open password (any user you share the PDF file with needs it) can remove the PDF restrictions in seconds.

  How to edit a password locked PDF

If a user has protected their PDF with Adobe Acrobat, editing it is easy.  This is especially true if they have the open password, which everybody who wants to view the document will need.

Here’s the simple, four-step process.

  1. Upload the document to an online password remover tool
  2. Enter the open password
  3. Wait for the website to strip the permissions password
  4. Download the modified PDF and edit it in any PDF editing software


If the open password is not immediately available, it does not mean a user cannot edit the PDF.  A PDF remover tool can still reveal or remove the open password given enough time.  It will also strip any editing controls from the document.

Alternatively, users can convert from PDF to another format by opening it in Google Docs or Microsoft Word and editing it that way.

  How to print a PDF that is locked with a password

The method to print a password-locked PDF is the same as above.  Users upload the protected document to an online service, download the unprotected version and hit “print”, or crack it with a PDF password remover tool.

If the document has any watermarks, they can of course edit the document to delete those before printing it.

So the Adobe method of locking PDFs to prevent changes provides zero protection since it can be easily defeated.  Printing a locked PDF is incredibly easy and so is removing any editing restrictions.

  Locking PDF files online

There are many PDF tools similar to Adobe that let you protect a PDF online.  The problem however is that you have to upload your unprotected PDF files to a cloud server where they could be compromised.  This might be OK for non-sensitive or non-confidential PDF documents, but most businesses do not want to expose their documents to a third party, which is why they are protecting them to begin with.

So, while online PDF locking tools may seem attractive, they are actually less secure and provide only simple password protection which is easily removed.

  How to lock PDF files securely without passwords using Safeguard

Safeguard PDF Security protects PDFs (encrypt PDFs) using public key technology.  There are no passwords to enter or remove or certificates to manage.

When you protect a PDF file, a corresponding key for the document is relayed to a server and stored encrypted.  This key is transferred in encrypted form to an authorized user’s computer when they open the PDF.  The key is held encrypted in a keystore which is locked to the authorized computer so it cannot be moved to another device.

  How to lock a PDF file from editing without passwords

  1. Right-click on a PDF on your computer and select ‘Make Secure PDF’.

    Creating a protected PDF file

  2. Select the copy protection controls you want to apply.  By default, editing, copying, and printing are disabled.

    Encrypting a PDF without passwords or certificates using Locklizard Safeguard PDF DRM

  3. Press the Publish button.
  4. Select the users you want to give access to your protected PDF files using the cloud-based Admin System:

    Safeguard Admin System

  5. Distribute your protected PDF documents like any other file.

The protected PDF file is now locked from editing, copying, printing and screen grabbing.  You can optionally add dynamic watermarks that cannot be removed, add expiry to the PDF, and prevent display settings from being changed.

When you lock a PDF file using Safeguard PDF Security, it encrypts the document and applies DRM controls.  Document protection is enforced regardless of where the PDF file is stored or who it is sent to, and PDFs are locked to machines (devices) so they cannot be shared.  If a locked PDF is sent to a unauthorized user they will not be able to open it since they need a decryption key.  If a user forwards their license file to another user, then it will not activate since it is a one-time use.

  How to lock a PDF form after filling out / fillable fields in PDF files

You can use Safeguard PDF Security to lock PDF forms and form fields from editing and form submissions from being altered after they have been filled out.

If you have a document that contains a form, then it will automatically be protected from editing – users can fill in fields but cannot edit form content.  You can also encrypt your PDF form fields on submission so that data in PDF form fields cannot be changed.

For more information see locking fields in PDF forms.

  What is a PDF Lock?


A PDF lock is a method or technique for denying access to PDF encoded information, such as locking a PDF with a password or registration code.

Some types of PDF protection are achieved with hardware – typically a ‘dongle’ which is a piece of hardware that must be present for the PDF to open.  Contrary to some recent ‘opinions’ the dongle is not obsolete and US law does not allow them to be removed UNTIL on an individual basis they are actually obsolete.

Most types of protection are implemented in software, and these may require entry of a password, registration codes, user identification codes, as well as network or machine addresses to be present or provided.

PDF protection has to make use of encryption to prevent anyone from being able to process the PDF without a suitable key.  However, there are different grades of protection:

  1. The simplest form of protection lets you encrypt your PDF with a password, which allows access to the content it is protecting.  This is not very effective because passwords can be given away, or cracked with password recovery tools.  Sometimes the password is also included with the document, which is not a very wise approach.
  2. A more secure solution will go much further.  It checks independently that the user/machine it is working on has been registered for the document in question, that it can obtain secrets needed to form the key, and that the use of the key is valid.  This kind of PDF protection is more subtle, and breaking it is much more complicated.

While a PDF lock shows some of the characteristics of physical locks – only opening at certain times and so on, it can go further by addressing how the file you’re protecting is subsequently used.  So, a strong protection system should consist of a granular and layered architecture – decide what features are to be unlocked, and even for how long, or under what circumstances – rather than a simple on/off mechanism.

Most importantly, it must be able to prevent authorized users from passing on information after it has been unlocked.

  Why lock PDF files?

The main reason to lock a PDF file is to control how the PDF document can be used and to prevent users from making changes to it.  The most common reasons are to:

  • prevent content from being edited
  • stop content from being copied and pasted
  • stop form content being changed or stop data in form fields from being edited after submission
  • block printing, allow only degraded printing, or restrict it to a specific number of prints
  • prevent it from being downloaded or saved
  • restrict use to a machine so it cannot be distributed to others
  • restrict access by IP address so it can only be used in certain locations
  • prevent changing of display settings so that content is presented in the way the document publisher wants

Most people use Adobe Acrobat to lock PDF files (or a similar PDF editor).  However these restrictions can be easily removed (or not even honored to begin with by some PDF Readers) so they are competely useless.  If you want to lock PDF files from editing and control their use, using a password or certificate is not the way forward since it provides no protection.

  Download PDF locking software: lock PDFs from being edited, copied, printed, saved


Download PDF protection software that uses US Government strength encryption and digital rights management controls to protect PDF files without passwords or certificates.

Prevent PDF files from being edited, copied, or printed.  Stop users saving PDF files to unprotected formats.  Restrict use to machines (devices) and locations so they cannot be shared, and prevent unauthorized sharing and distribution.

Safeguard PDF Security and Enterprise PDF DRM are a secure alternative to Adobe Acrobat PDF password protection, allowing you to protect PDF files for viewing on Windows, Mac, iOS, Android, or for online use in a browser.

See our customer testimonials and read our case studies to see why thousands of organizations use Locklizard PDF security to restrict PDF use, securely share documents and securely sell documents.

  FAQs

Locklizard Safeguard provides an effective way to protect your PDF from editing after it has been signed.  Unlike Adobe Acrobat, its editing and printing prevention controls cannot be removed.

If you don’t do this, then another user can just remove the signature (either a digital signature or an e-signature).

If you want users to sign a document using a physical signature, then it is recommended that you protect a PDF with Safeguard before you send it for signing to ensure the user cannot modify or copy it before they send it back.  You can allow a single print in your Safeguard protection options and have them send the physical copy or scan back to you.

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