What is encryption?

Encryption is the conversion of information into a format that is unreadable by unauthorized users. An encrypted computer file can only be opened with the appropriate key or password. When an encrypted message is converted to readable information, it is said to be decrypted.

When should I use encryption?

Users having confidential information under their custody have the responsibility to prevent it from leakage or unauthorized access. Confidential files downloaded to a portable storage media, such as USB thumb drive, must be encrypted. Loss of USB thumb drives or other portable storage media with strongly encrypted files is considered to have lower risk of information leakage because it is very difficult to break the password. Mobile devices (i.e. smartphones and tablet) pose the same risk in information leakage as desktop and laptop computers. Users should take the necessary precautions and steps to encrypt and delete confidential data.

OCIO recommends the AES-256 or stronger encryption standards to encrypt sensitive information. There are a number of software applications that support the use of these encryption standards, e.g. WinZip + password, Acrobat (PDF) + password, MS Word/Excel + password, and BitLocker.

Please refer to the following on different encryption procedures:

• Email labelling and file protection using Microsoft Purview Information Protection (MIP)
• How to password protect my documents with 7-ZIP?
• How to apply open password on a PDF file?
• How to apply open password on Word, Excel file?
• Data protection with VeraCrypt
• Data protection with BitLocker
• Create a secure disk image on macOS

Finally, the loss of encryption password of the encrypted document will mean the file can never be opened.