Choose the right file
Before uploading, check that you are sending the correct version and that it contains no unnecessary personal information. Redacting an unnecessary page is often a stronger privacy improvement than changing a cryptographic setting.
Encrypt and upload
Chat256's media architecture is designed to encrypt supported media client-side, transfer it in chunks and enforce authenticated access, quotas and expiry. The server still needs to manage ciphertext, transfer state and access control.
Check the recipient
The strongest file encryption cannot compensate for sending the file to the wrong person. Confirm the intended conversation before uploading a sensitive document.
Choose retention
Use temporary storage or expiry where the file only needs to exist for a limited period. For longer-lived project material, Workspace provides a separate organisational surface from the chat stream.
After download
Remember that the recipient now has a local copy. If the file is highly sensitive, agree how it should be stored, copied and deleted. Application-side expiry cannot erase a downloaded copy.