GPG (PGP)

Files.com encrypts your files in transit and at rest by default. Sometimes counterparties or compliance requirements call for GPG or PGP encryption on top of that. Files.com supports automatic GPG encryption or decryption of any file that arrives in a specific folder.

You can configure different folders to use different GPG keys, giving each folder its own encryption.

About GPG

GPG stands for GNU Privacy Guard, an independent implementation of PGP.

PGP, or Pretty Good Privacy, was originally developed as freeware under the GNU public license to allow the secure transfer of information with strong encryption. PGP was later turned into a proprietary program.

GPG is a publicly licensed project of the OpenGPG Alliance and is used interchangeably with PGP.

How GPG Encryption Works

GPG encryption is separate from the at-rest encryption that Files.com applies by default. It uses a public GPG key that you provide when enabling GPG encryption for a folder.

Once files are encrypted with your public key on upload, they can only be decrypted with the corresponding private key, which only you control. The files are unreadable to anyone (including Files.com) without that private key.

Exact Timing of Encryption and Decryption

GPG runs as a post-processing step after an upload.

Moving a file into the folder does not trigger GPG encryption or decryption, and neither does renaming a file. This holds whether the move or rename is performed manually or by an Automation.

Copying a file into the folder triggers GPG encryption or decryption in the same way as an upload. This also holds when the copy is performed by an Automation or a Sync action.

A Sync configured to pull (upload) files into the folder triggers GPG encryption and decryption just as if the files were uploaded manually.

When a file requires post-processing, it is first locked and quarantined as part of the upload process. The quarantined file is streamed into GPG, and encryption or decryption is applied on the fly as the output file is written to the destination folder. The original file is unavailable for any actions until post-processing is complete, after which it is deleted and purged.

The output of the GPG encryption or decryption appears as a newly created (uploaded) file in the destination folder and can trigger any Automations configured to fire when files are created.

Notifications, including Folder Settings email notifications, Slack notifications, and Webhooks, fire on the resulting output file of the GPG encryption or decryption.

The file appears in list requests through certain interfaces (FTP, SFTP, and some other integrations) during this state. We intend to soon enhance our web interface and Desktop app to indicate when a file is in this locked state and to show post-processing status. Despite appearing in a list, the file is unavailable for any action other than delete until post-processing is complete.

GPG on Remote Server Mounts

When GPG is enabled on a folder that uses a Remote Server Mount, Files.com uses buffered uploading rather than streaming the file directly to the remote server. The file is temporarily stored on Files.com, encrypted at rest using Files.com's standard storage encryption, GPG-encrypted, and then forwarded to the Remote Server.

This store-and-forward process is required because GPG needs access to the complete file before processing it.

Buffered uploading cannot be disabled for GPG folders. It overrides the Buffered Upload setting of your Remote Server and is not reflected in the Remote Server's settings. If you use Remote Server Mounts specifically to prevent file data from residing on Files.com infrastructure then you should factor this in before enabling GPG on a mounted folder.

File Size Constraints

Files.com currently performs GPG encryption, decryption, and recryption only on files up to 5 GB. This limit reflects how we host the GPG application in the cloud. We are interested in learning about the use case of any customers who need GPG for very large files.

Overwrite Behavior for Output Files

The output of an encryption or decryption does not overwrite an existing file. Instead, the new output file's name is appended with a date and time value to make it unique, so existing output files with matching names are preserved and no data is lost.

Signing Constraints

Files that are both encrypted and signed are decrypted successfully, but no signature verification is performed.