How UniMe implement the secured end-to-end chat app
UniMe is a universal secured chat app and AI Chatbot/Blockchain hub. This is one of the Uniworld’s applications that provides an easy way for end-users to interact with Uniworld’s ecosystem. UniMe can be used as a normal messenger application except that all chat, data, audio/videos are encrypted from end-to-end, so that only involved participants can decode and understand the content of chats, audio/video calls. Moreover, users can use UniMe to create a Chatbot or create the chatbot conservation, interact with Bot and AI systems as well as manage their blockchain/crypto wallet, smart contracts and decentralized applications. In post, let’s discovery how UniMe implement secured end-to-end chat app.
UniMe secured end-to-end chat application is implemented according to TextSecure protocol (as known as Signal protocol) . The protocol can be roughly divided into three types of stages:
- The initial key exchange, or X3DH (extended triple Diffie-Hellman) protocol , which combines long-term, medium-term and ephemeral Diffie-Hellman keys to produce a shared secret “root” value.
- An asymmetric ratchet stage, where users alternate in sending new ephemeral Diffie-Hellman keys in a ping-pong fashion with previously generated root keys to generate forward-secret chaining keys.
- A symmetric ratchet stage, where users take no additional entropy but instead use key derivation functions to ratchet forward chaining keys to create symmetric encryption keys.
Each message sent by a user is encrypted using a fresh message key, which attempts to provide a high degree of forward secrecy. The ping-pong pattern of new ephemeral Diffie-Hellman keys inject additionally entropy into this process, which is intended to continually achieve perfect forward secrecy as well as post-compromise security
As stated above, We can divide protocol as a multi-stage authenticated key exchange protocol.
The multi-stage authenticated key exchange protocol has the following main steps:
- Registration: At installation (and periodically afterwards), both Alice and Bob independently register their identity with a key distribution server and upload some long-term, medium-term, and ephemeral public keys.
- Session setup: Alice requests and receives a set of Bob’s public keys from the key distribution server and uses them to set up a long-lived messaging session and establish initial symmetric encryption keys. This is called the TripleDH handshake or X3DH.
- Synchronous messaging: (a.k.a. asymmetric-ratchet updates) When Alice wants to send a message to Bob (or vice versa) and has just received a message from Bob, she exchanges Diffie–Hellman values with Bob, generating new shared secrets and uses them to begin new chains of message keys. Each DH operation is a stage of the “asymmetric ratchet” (and strictly occurs in a ping-pong fashion).
- Asynchronous messaging: (a.k.a. symmetric-ratchet). When Alice wants to send a message to Bob (or vice versa) but has not received a message from Bob since her last sent message to Bob, she derives a new symmetric encryption key from her previous state using a PRF. Each PRF application is a stage of the “symmetric ratchet”
UniMe follows the microservice architecture for better scale and management. The following picture illustrates UniMe architecture at a high level.
UniMe has finished the first phase of development, Application is available on:
Download UniME world for IOS device.
Download UniMe world for Android device.