I want to use whisper to implement a chat room in my dapp. I learned about whisper, if you want to realize the function of private chat, you need to know the public key of other people. For a user who has just logged in the chat room, how does he obtain the public keys of other people. One way I currently think of is to store the private keys of the logged-in users in the smart contract, so that the newly logged-in user can obtain the public keys of other users through the smart contract, and then realize private chat. I want to know if there are other better ways to get the private keys of other users.
Hope you can give me some help, thanks!