diff --git a/src/server/dispatch_server.rs b/src/server/dispatch_server.rs
index 5b29b4f..df30928 100644
--- a/src/server/dispatch_server.rs
+++ b/src/server/dispatch_server.rs
@@ -4,6 +4,8 @@ use std::net::TcpStream;
 use std::collections::HashMap;
 use std::fs;
 use std::sync::Arc;
+use std::fs::read_to_string; // use instead of std::fs::File
+use std::path::Path;
 
 extern crate futures;
 extern crate base64;
@@ -11,15 +13,21 @@ extern crate actix_web;
 extern crate openssl;
 
 use serde::{de, Deserialize, Deserializer, Serialize};
+use serde::de::Error;
 use futures::executor;
 
 use actix_web::{rt::System, web, get, App, HttpRequest, HttpResponse, HttpServer, Responder, middleware::Logger};
 use openssl::ssl::{SslAcceptor, SslFiletype, SslMethod, SslVerifyMode, SslOptions, SslMode};
+use openssl::rsa::{Rsa, Padding};
+use openssl::symm::Cipher;
 use rand::{distributions::Alphanumeric, Rng};
 
 use prost::Message;
 
 use mhycrypt;
+use openssl::hash::MessageDigest;
+use openssl::pkey::{PKey, Private, Public};
+use openssl::sign::Signer;
 use pretty_env_logger::env_logger::fmt;
 use serde::de::Unexpected;
 //use openssl::rand;
@@ -27,6 +35,34 @@ use serde::de::Unexpected;
 #[derive(Clone)]
 pub struct DispatchServer {}
 
+// Keys stuff
+#[derive(Deserialize,Debug)]
+struct KeyInfo {
+    key_id: u8,
+    #[serde(deserialize_with = "deserialize_pub_key")]
+    public_key: Rsa<Public>,
+    #[serde(deserialize_with = "deserialize_priv_key")]
+    private_key: Rsa<Private>,
+}
+
+fn deserialize_pub_key<'de, D>(deserializer: D) -> Result<Rsa<Public>, D::Error>
+    where
+        D: Deserializer<'de>,
+{
+    let public_key_pem: &str = Deserialize::deserialize(deserializer)?;
+
+    Rsa::public_key_from_pem(public_key_pem.as_bytes()).map_err(D::Error::custom)
+}
+
+fn deserialize_priv_key<'de, D>(deserializer: D) -> Result<Rsa<Private>, D::Error>
+    where
+        D: Deserializer<'de>,
+{
+    let private_key_pem: &str = Deserialize::deserialize(deserializer)?;
+
+    Rsa::private_key_from_pem(private_key_pem.as_bytes()).map_err(D::Error::custom)
+}
+
 #[derive(Deserialize,Debug)]
 struct ClientInfo {
     version: String,
@@ -37,6 +73,7 @@ struct ClientInfo {
     channel_id: i32,
     sub_channel_id: i32,
     account_type: Option<i32>,
+    key_id: Option<u8>,
 }
 
 #[derive(Deserialize,Debug)]
@@ -268,7 +305,39 @@ impl DispatchServer {
 
         region_config.encode(&mut region_conf_buf).unwrap();
 
-        return base64::encode(region_conf_buf);
+        if c.0.version.contains("2.7.5") || c.0.version.contains("2.8.") {// TODO: use proper version check!
+            let key_id = match c.0.key_id {
+                Some(key_id) => key_id,
+                None => panic!("Client version >= 2.7.50, but it haven't provided key_id!"),
+            };
+            let rsa_key_collection = DispatchServer::load_rsa_keys("RSAConfig");
+            let keys = match rsa_key_collection.get(&key_id) {
+                Some(keys) => keys,
+                None => panic!("Unknown key ID {}!", key_id),
+            };
+
+            let mut out_buf: Vec<u8> = Vec::new();
+            let mut enc_buf: Vec<u8> = vec![0; keys.public_key.size() as usize];
+
+            for chunk in region_conf_buf.chunks(245) { // TODO: value hardcoded for the 2048-bit key!
+                keys.public_key.public_encrypt(chunk, &mut enc_buf, Padding::PKCS1).unwrap();
+                out_buf.append(&mut enc_buf);
+            }
+
+            let keypair = PKey::from_rsa(keys.private_key.clone()).unwrap();
+            let mut signer = Signer::new(MessageDigest::sha256(), &keypair).unwrap();
+            signer.update(&region_conf_buf).unwrap();
+            let signature = signer.sign_to_vec().unwrap();
+
+            return format!("
+            {{
+                \"content\": \"{}\",
+                \"sign\": \"{}\"
+            }}
+            ", base64::encode(out_buf), base64::encode(signature));
+        } else {
+            return base64::encode(region_conf_buf);
+        }
     }
 
     async fn risky_api_check_old(a: web::Json<ActionToCheck>) -> String {
@@ -634,6 +703,16 @@ impl DispatchServer {
         return "127.0.0.1".to_string();
     }
 
+    fn load_rsa_keys(name: &str) -> HashMap<u8, KeyInfo> {
+        // Key depo
+        let path = format!("./{}/{}.json", "keys", name);
+        let json_file_path = Path::new(&path);
+        let json_file_str = read_to_string(json_file_path).unwrap_or_else(|_| panic!("File {} not found", path));
+        let data: Vec<KeyInfo> = serde_json::from_str(&json_file_str).expect(&format!("Error while reading json {}", name));
+
+        data.into_iter().map(|ki| (ki.key_id, ki)).collect()
+    }
+
     fn load_keys(name: &str) -> (Vec<u8>, Vec<u8>) {
         // Key
         let filename = format!("./{}/{}.key", "keys", name);