Messaging - SafeSlingerProject/SafeSlinger-Media GitHub Wiki

For detailed information on our end-to-end security see our messaging encryption scheme and how we manage keys.

Sending Messages

Before sending messages you need to sling keys with at least one other user. Our messaging instructions page provides a short walkthrough to use the application.

Message Longevity

Currently we keep messages available on our server to download for 24 hours.

Group Chat

SafeSlinger currently only supports sending one message to any user at a time. A group chat feature is currently under development, let us know if you want to contribute.

Attachments

Attachments are limited to 9 MB in size and can be in any format. SafeSlinger currently only supports adding one attachment to a message at a time.

Storage

Messages are kept in the app database on your phone, and require a passphrase to access. Attachments (pictures, documents) are saved to the operating file system storage or storage card so you can manage them with the default application for each type of attachment (Gallery, Document Viewer). We suggest users use their discretion after decrypting message attachments and delete them as appropriate.

Push Message Notification

To avoid text-messaging charges and conserve battery energy, we make use of smartphone operating systems’ support for push notifications to deliver message data. Rather than requiring each application developer to implement a background task to keep a separate connection to their server to poll for updates, push notifications are an OS-provided unified update service in which the OS maintains one connection to its own service. Then, each developer can register their application with the OS’ service, and the OS only needs to maintain one connection to check for updates across several applications.