I'm developing a chat application using Substrate and facing a specific issue regarding user notifications. My application needs to notify users when they have a new message in a chat channel. Initially, I considered using Substrate's event system for this purpose. However, the issue is that when an event is emitted, other users can also access that event and potentially read the message content( in explorer ) .
My Questions:
What strategies can I employ to securely notify users about new messages in a Substrate-based chat application without compromising message privacy?
Is there a way to make events private or restricted to certain users in Substrate?
Are there any existing Substrate modules or cryptographic techniques that could help me maintain user privacy while also notifying them of new messages?