ENCRIPTY END-TO-END

• Public key (use to encrypt chat key)
• Private key (use to decrypt chat key)
• Tranfer key (use to get chat key)
• Chat key (use to encrypt and decrypt messages)

1 STEP - CONFIG

• Create a public and private key on server

2 STEP - GET PUBLIC KEY

• Server returns public key to the user

3 STEP - CREATE A NEW CHAT

• Generate a chat key (e.g. %SECRET_CHAT%)
• Encrytp the chat key by public key
• Save the encrypt key on the chat

On client

const chatKey = uuid(); // %SECRET_CHAT%
const encryptedChatKey = encrypt(chatKey, public_key); // #ENCRYPTED_SECRET_CHAT#

const request = { uid: "1", key: encryptedChatKey };

4 STEP - GET CHAT KEY

On client

• Generate a new key (e.g. @KEY@)
• Encrytp the key by public key
• Send the id's chat and the new key the server

const transferKey = uuid(); // @KEY@;
const encryptedTransferKey = encrypt(transferKey, public_key); // @ENCRYPTED_KEY@

const request = { uid: "1", key: encryptedTransferKey }; // { uid: '1', key: @ENCRYPTED_KEY@ }

On server

• Get the chat data by id
• Decrypt the chat key
• Decrypt the transfer key
• Encrypt the chat key by the transfer key
• Responds the the decrypt key to the client

const { body } = request; // { uid: '1', key: @ENCRYPTED_KEY@ }

const chat = getChatById(body.uid); // { uid: '1', key: '#ENCRYPTED_SECRET_CHAT#' }

const decryptedChatKey = decrypt(chat.key, private_key); // %SECRET_CHAT%
const transferKey = decrypt(body.key, private_key); // @KEY@
const decryptKey = encrypt(decryptedChatKey, transferKey); // $ENCRYPTED_DECRYPT_KEY$

const response = { decryptKey }; // { hashKey: '$KEY$' }

On client

• Use the transferKey to decrypt the decryptKey
• Use the chat key to decrypt or encrypt the messages

const transferKey = uuid(); // @KEY@; // '@KEY@';
const { decryptKey } = response; // $ENCRYPTED_DECRYPT_KEY$
const chatKey = decrypt(decryptKey, transferKey); // %SECRET_CHAT%
const message = decrypt("H3110 W0R1D!", chatKey); // "Hello World!"