How Inboxes Work
This page covers the mechanism behind both kinds of inbox. For what an inbox is and which one to deploy, start with Inboxes.
An inbox is a directory
An inbox is an ordinary directory in a user's Vault that has been opened to outside senders. Files that arrive in it can be shared, downloaded, and viewed like any other file the user owns, because that is what they are.
The import uses the owning user's public key, so files are encrypted before they come to rest. Only the user who set up the inbox holds the matching private key, and only they can decrypt what arrives. This holds against the service that received the file and against an administrator with access to the storage underneath it.
Senders never get read access. To give a file back to a contributor, a tiCrypt user has to download it first, taking responsibility for it. In practice the people with that permission are admins and project leaders.
An inbox receives files from outside contributors. It is not a way to send files out of tiCrypt.
Access points
Each inbox has one or more access points. The access point is what the sender is given, and it carries its own limits: an expiration date and an upload capacity. Revoking an access point closes that one route without touching the inbox or anything already delivered into it.
There are two types:
- URL. The sender is given a link and uploads through a web browser. Nothing is installed on their machine.
- SFTP. Opening the link issues one-time SFTP credentials for that sender, which they use with any SFTP client. This is the type to use for large transfers and whole directory trees.
Automatic locking
If a sender is impersonated and a malicious file is pushed through an access point, the inbox locks itself. Encryption on arrival means the contents are unreadable even in that case, so the lock protects the workflow rather than the data.
Hosting the URL inbox application
A URL inbox needs a website to deliver its single-page application, and the inbox settings in the system configuration or in the global system settings must point at that website. The application can be hosted anywhere, independently of where the tiCrypt server runs, because it talks to the backend over the REST API like any other client.
See URL Inbox Configuration for the settings, and SFTP Inbox Configuration for the SFTP service.