Skip to main content

Trinity College Dublin, The University of Dublin

Trinity Menu Trinity Search

IT Services Knowledge Base

You are here Keeping IT Secure > Document and file encryption

Document and file encryption

When documents are created, stored, sent and shared, they have the potential to be openly accessible to anyone. Further risks are involved once a document arrives at its destination. This is why it is vital to understand how you can protect your documents.

Below is information on what document encryption is and how to encrypt Office documents or a new PDF converted from a Word document, and how to encrypt Adobe documents.

Important note on encrypting your documents

Store your password in a safe place and only share when intended. If you don't remember your password, then you won’t be able to open your file and you will lose access to the information in this file. IT Services cannot retrieve your forgotten password.

What is document encryption/password protection?

Encryption by definition is a process of encoding information to prevent unauthorized persons from accessing it.

Password protecting information, including documents, is a level of encryption that protects against information reaching unintended audiences. 

Using these document password protection capabilities provides a number of good benefits, with the three most critical benefits being:

  1. Only recipients that know the password can open the document and more importantly read its content
  2. This level of protection goes with the document no matter where it is stored or sent.
  3. Tampering with a protected document takes time and effort providing another deterrent to efforts to access its content

Even if your email is intercepted or sent to someone unexpected, or your server is hacked and your files are compromised, having the information individually encrypted means another degree of protection, further reducing your overall exposure.

Adding (and removing) encryption for Office documents

To add encryption to an Office document:

To set a password on your Word, Excel or PowerPoint file click File > Info > Protect Document > Encrypt with Password. You'll be prompted to create a password, then to confirm it. After you've added a password to your file you'll want to be sure to save the file to make sure the password takes effect.

To remove encryption from an Office document:

Open the file, which will require the current password, go to File > Protect Document > Encrypt with Password. Delete the password and click OK. Be sure to save your file to make that change permanent.

Adding a password to Adobe Documents

You can limit access to a PDF by setting passwords and by restricting certain features, such as printing and editing. However, you cannot prevent saving copies of a PDF. The copies have the same restrictions as the original PDF.

You can set two types of passwords for your PDF:

  • Document Open Password: this is a password that someone will need to open the protected PDF
  • Permissions Password: this is a password that will allow someone to change the settings on the protected PDF

To add a password:

  1. Open the PDF and choose Tools > Protect > Encrypt > Encrypt with Password

  2. If you receive a prompt, click Yes to change the security

  3. Select Require A Password To Open The Document, then type the password in the corresponding field. For each keystroke, the password strength meter evaluates your password and indicates the password strength.

  4. Select an Acrobat version from the Compatibility drop-down menu. Choose a version equal to or lower than the recipients’ version of Acrobat or Reader.

  5. Select an encryption option:
    Encrypt All Document Contents: Encrypts the document and the document metadata. If this option is selected, search engines cannot access the document metadata.
    Encrypt All Document Contents Except Metadata: Encrypts the contents of a document, but still allows search engines access to the document metadata.
    Encrypt Only File Attachments: Requires a password to open file attachments. Users can open the document without a password.

  6. Click OK. At the prompt to confirm the password, retype the appropriate password in the box and click OK.

Encrypting a new PDF, converted from a Word document

  1. With your document open, select the File tab

  2. Click Save As and then choose a desired location for the document to reside

  3. From the Save As dialogue box, select PDF from the Save As type dropdown list

  4. Click the Options button

  5. From the Options dialogue box, check Encrypt the document with a password

  6. You are now prompted to enter a password. It is recommended that you use a strong password or passphrase; store this information in a safe place!

  7. Click OK

  8. From the Save As dialogue box, click Save

  9. Your file is not encrypted and will require a password to be opened.

Related links