When a document contains personally-identifying information, it needs to be encrypted before it can be shared with others electronically, via email, or through file sharing (on a file server, via Google Drive or other similar means, etc.) Documents should be encrypted prior to sharing with a password. This document describes how to encrypt common document formats, including PDF files, Word documents, and Excel documents.

NOTE: Tips for sharing passwords with document recipients

• Recipients should receive the password for any encrypted document using means other than how they were distributed.

  • For example, if you share an encrypted document as an email attachment, do not use email to share the password with the recipient(s).

• The most secure method for sharing the password is in person, but you an also provide the password via SMS/text message, voicemail, or postal letter.

  • Never reference the encrypted document in the same communication or message that contains the password.

• A password by itself is meaningless to someone, but a password which references an encrypted document provides a malicious actor with a reference and motivation.

  • Think of the password as the key to a locked door. If you lose the key, and someone finds it, but the key is not labeled, it will be difficult for them to match the key with any locked door. If on the other hand you labeled the key in some fashion - with a postal address for a house key, or a license plate number for an automobile - anyone who finds the key knows what it is for.

• Do not name documents containing sensitive information with descriptive titles that describe the sensitive contents.

  • These types of naming schemes essentially provide malicious actors with a clear sign that the document contains information or data worth stealing. For example, a spreadsheet named Student Social Security Numbers.xlsx would bring the attention of a malicious actor, while a document with identical contents, but named more generically Report-082319.xlsx would not.

How to encrypt common document formats

Encrypt a PDF file

Adobe Acrobat PDF files can be encrypted with a password which will make the contents unreadable to anyone who does not have the password.

Using Adobe Acrobat

To encrypt a file using the Adobe Acrobat application on Windows or macOS computers, use the instructions provided here:

https://helpx.adobe.com/acrobat/using/securing-pdfs-passwords.html

Using macOS Preview

To encrypt a file using the Preview application on macOS computers, use the instructions provided here:

https://support.apple.com/guide/preview/password-protect-a-pdf-prvw587dd90f/mac

Encrypt Microsoft Word and Excel files

Microsoft Office Word and Excel files can be encrypted with a password which will make the contents unreadable to anyone who does not have the password.

Using Microsoft Word

Microsoft Word files can be encrypted with a password which will make the contents unreadable to anyone who does not have the password.

To encrypt a file using the Microsoft Word on Windows or macOS computers, use the instructions provided here:

https://support.office.com/en-us/article/protect-a-document-with-a-password-05084cc3-300d-4c1a-8416-38d3e37d6826

Select the appropriate version on the page, and follow the instructions provided:

Using Microsoft Excel

Microsoft Excel files can be encrypted with a password which will make the contents unreadable to anyone who does not have the password.

To encrypt a file using the Microsoft Excel on Windows computers, use the instructions provided here: 

https://support.office.com/en-us/article/protect-an-excel-file-7359d4ae-7213-4ac2-b058-f75e9311b599

To encrypt a file using the Microsoft Excel on macOS computers, use the instructions provided here: 

https://support.office.com/en-us/article/require-a-password-to-open-or-modify-a-workbook-10579f0e-b2d9-4c05-b9f8-4109a6bce643

Select the appropriate version on the page: