CRYPTO NEWS

How to use symmetric encryption on 1on1 and group chat messenger?

Hi everyone so currently I’m trying to learn about encryption to build secure messaging app (Mobile-app, flutter based). I want the app to have 2 messaging features which are 1 on 1 messaging and group-chat messaging. Firstly I wanted to try using symmetric encryption for the app, but there are some question that make me a little bit confused:

1. When using symmetric encryption, assuming that each user have their own key. When Person A send message Person B should we fetch the person A key or person B key for the encryption ?

2. What’s the best practice to store the user key ? can I just generate the key and keep it in the cloud database ?

3. Can I do like some double AES algorithm for the encryption? So the potential hacker will have to do more work for altering the system (1 main app Key, 1 user key)

4. How does symmetric encryption work for group chat messenger ? I don’t get the flow logic

What `to` should be set when deploying contracts?

I’m deploying contract using eth_sendTransaction and compiled bytecode. So for example my transaction is: { from: "0x0000123…", data: "0x6000…", gas: "0x9999", gasPrice: "0x9999", to: ???? whats here? } I’m just wondering what should to address be set? Are people creating new account address in wallet apps, and deploying contracts to that address? What’s the typical ::Listen

I’m deploying contract using eth_sendTransaction and compiled bytecode.

So for example my transaction is:

{    from: "0x0000123...",    data: "0x6000...",    gas: "0x9999",    gasPrice: "0x9999",    to: ???? whats here? }

I’m just wondering what should to address be set? Are people creating new account address in wallet apps, and deploying contracts to that address? What’s the typical protocol here?

Thanks