Yeah no kidding that's the code I'm referencing. NIP 4 was the link I was sent by SebasWouters when I asked what encryption algorithm its using.

nerd2ninja

The code looks familiar. It seems they are implementing nip 4, encrypted DMs, to send messages back and forth. 
It generates a shared secret, based on the sender's private key and the recipient's public key to encrypt the message (I think) so that the recipient can decrypt it. 


nostr

emon: encrypted messaging over nostr with lightning integration ⚡

SebasWouters

```javascript
let sharedPoint = secp.getSharedSecret(ourPrivateKey, '02' + theirPublicKey)
```
Secp from what I understand, is only supposed to be for digital signatures. I currently understand that any encryption done with it could be cracked kinda easy.

```javascript
let sharedX = sharedPoint.substr(2, 64)
```

```javascript
var cipher = crypto.createCipheriv(
  'aes-256-cbc',
  Buffer.from(sharedX, 'hex'),
  iv
)
```

Still don't understand how the recepiant is getting the decryption key