diff --git a/.gitignore b/.gitignore
index 53eaa21..4157dcc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 /target
 **/*.rs.bk
+/iana-tlds.txt
+/iana-hashes.txt
diff --git a/Cargo.toml b/Cargo.toml
index 427dade..2b07647 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,6 +42,8 @@ winapi = { version = "0.3.7", features = ["impl-default", "wincon"]}
 thread-priority = "0.2.1"
 
 [build-dependencies]
+minreq = { version = "2.3.1", features = ["punycode", "https-rustls"] }
+rust-crypto = "^0.2"
 winres = "0.1"
 
 [dev-dependencies]
diff --git a/build.rs b/build.rs
index a2b3ed7..2c63cc7 100644
--- a/build.rs
+++ b/build.rs
@@ -1,9 +1,67 @@
 extern crate winres;
 
+use std::fs::File;
+use std::path::Path;
+use std::io::Write;
+
+use crypto::digest::Digest;
+use crypto::sha2::Sha256;
+
 fn main() {
     if cfg!(target_os = "windows") {
         let mut res = winres::WindowsResource::new();
         res.set_icon("globe_icon.ico");
         res.compile().unwrap();
     }
+
+    download_iana_zones("iana-tlds.txt", "iana-hashes.txt");
+}
+
+fn download_iana_zones(zones_name: &str, hashes_name: &str) {
+    let response = minreq::get("https://data.iana.org/TLD/tlds-alpha-by-domain.txt").send().expect("Could not make request!");
+
+    let response = response.as_str().expect("Response is not a valid UTF-8!").to_lowercase();
+    let list: Vec<_> = response.split("\n").collect();
+    let mut zones = String::new();
+    let mut hashes = String::new();
+    for string in list {
+        if !string.starts_with("#") && !string.is_empty() {
+            zones.push_str(string);
+            zones.push('\n');
+
+            hashes.push_str(&hash_identity(string));
+            hashes.push('\n');
+        }
+    }
+
+    match File::create(Path::new(zones_name)) {
+        Ok(mut file) => {
+            file.write_all(zones.trim().as_bytes()).expect("Error saving TLDs file!");
+        }
+        Err(e) => { println!("Error opening TLDs file!\n{}", e); }
+    }
+
+    match File::create(Path::new(hashes_name)) {
+        Ok(mut file) => {
+            file.write_all(hashes.trim().as_bytes()).expect("Error saving TLD-hashes file!");
+        }
+        Err(e) => { println!("Error opening TLD-hashes file!\n{}", e); }
+    }
+}
+
+fn hash_identity(identity: &str) -> String {
+    let mut buf: [u8; 32] = [0; 32];
+    let mut digest = Sha256::new();
+    digest.input_str(identity);
+    digest.result(&mut buf);
+    to_hex(&buf)
+}
+
+/// Convert bytes array to HEX format
+pub fn to_hex(buf: &[u8]) -> String {
+    let mut result = String::new();
+    for x in buf.iter() {
+        result.push_str(&format!("{:01$X}", x, 2));
+    }
+    result
 }
\ No newline at end of file
diff --git a/src/context.rs b/src/context.rs
index 33743ca..0aa8bff 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,4 +1,4 @@
-use crate::{Chain, Bus, Keystore, Settings};
+use crate::{Chain, Bus, Keystore, Settings, Iana};
 use crate::event::Event;
 #[allow(unused_imports)]
 use log::{trace, debug, info, warn, error};
@@ -7,13 +7,14 @@ pub struct Context {
     pub settings: Settings,
     pub keystore: Keystore,
     pub chain: Chain,
+    pub iana: Iana,
     pub bus: Bus<Event>,
 }
 
 impl Context {
     /// Creating an essential context to work with
     pub fn new(settings: Settings, keystore: Keystore, chain: Chain) -> Context {
-        Context { settings, keystore, chain, bus: Bus::new() }
+        Context { settings, keystore, chain, iana: Iana::new(), bus: Bus::new() }
     }
 
     /// Load keystore and return Context
diff --git a/src/iana.rs b/src/iana.rs
new file mode 100644
index 0000000..da58145
--- /dev/null
+++ b/src/iana.rs
@@ -0,0 +1,28 @@
+use std::collections::HashSet;
+
+pub struct Iana {
+    zones: HashSet<String>,
+    hashes: HashSet<String>
+}
+
+impl Iana {
+    pub fn new() -> Self {
+        let zones: HashSet<_> = include_str!("../iana-tlds.txt")
+            .split("\n")
+            .map(String::from)
+            .collect();
+        let hashes: HashSet<_> = include_str!("../iana-hashes.txt")
+            .split("\n")
+            .map(String::from)
+            .collect();
+        Self { zones, hashes }
+    }
+
+    pub fn has_zone(&self, zone: &str) -> bool {
+        self.zones.contains(zone)
+    }
+
+    pub fn has_hash(&self, hash: &str) -> bool {
+        self.hashes.contains(hash)
+    }
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 9032aa3..19b14bd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,6 +8,7 @@ pub use crate::p2p::Network;
 pub use crate::settings::Settings;
 pub use crate::bytes::Bytes;
 pub use crate::keys::Keystore;
+pub use crate::iana::Iana;
 pub use crate::simplebus::*;
 pub use crate::utils::*;
 
@@ -23,4 +24,5 @@ pub mod dns;
 pub mod dns_utils;
 pub mod settings;
 pub mod bytes;
+pub mod iana;
 
diff --git a/src/p2p/network.rs b/src/p2p/network.rs
index bd7722e..718a5e3 100644
--- a/src/p2p/network.rs
+++ b/src/p2p/network.rs
@@ -355,6 +355,12 @@ fn handle_message(context: Arc<Mutex<Context>>, message: Message, peers: &mut Pe
             };
             let peer = peers.get_mut_peer(token).unwrap();
             peer.set_received_block(block.index);
+            if let Some(transaction) = &block.transaction {
+                if context.lock().unwrap().iana.has_hash(&transaction.identity.to_string()) {
+                    // This peer has mined some of the forbidden zones
+                    return State::Banned;
+                }
+            }
             let context = context.clone();
             let peers_count = peers.get_peers_active_count();
             thread::spawn(move || {
diff --git a/src/web_ui.rs b/src/web_ui.rs
index da53c6d..8c1a0e5 100644
--- a/src/web_ui.rs
+++ b/src/web_ui.rs
@@ -164,11 +164,11 @@ pub fn run_interface(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>) {
                         };
                         match transaction {
                             None => {
-                                create_domain(miner.clone(), name, records, &keystore);
+                                create_domain(context.clone(), miner.clone(), name, records, &keystore);
                             }
                             Some(transaction) => {
                                 if transaction.pub_key == keystore.get_public() {
-                                    create_domain(miner.clone(), name, records, &keystore);
+                                    create_domain(context.clone(), miner.clone(), name, records, &keystore);
                                 } else {
                                     warn!("Tried to mine not owned domain!");
                                     let _ = web_view.eval(&format!("showWarning('{}');", "You cannot change domain that you don't own!"));
@@ -185,7 +185,7 @@ pub fn run_interface(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>) {
                 TransferDomain { .. } => {}
                 CheckZone { name } => {
                     let name = name.to_lowercase();
-                    if !check_domain(&name, false) {
+                    if !check_domain(&name, false) || context.lock().unwrap().iana.has_zone(&name) {
                         web_view.eval("zoneAvailable(false)").expect("Error evaluating!");
                     } else {
                         let c = context.lock().unwrap();
@@ -202,11 +202,11 @@ pub fn run_interface(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>) {
                     };
                     match transaction {
                         None => {
-                            create_domain(miner.clone(), name, data, &keystore);
+                            create_domain(context.clone(), miner.clone(), name, data, &keystore);
                         }
                         Some(transaction) => {
                             if transaction.pub_key == keystore.get_public() {
-                                create_domain(miner.clone(), name, data, &keystore);
+                                create_domain(context.clone(), miner.clone(), name, data, &keystore);
                             } else {
                                 warn!("Tried to mine not owned domain!");
                                 let _ = web_view.eval(&format!("showWarning('{}');", "You cannot change domain that you don't own!"));
@@ -253,14 +253,17 @@ pub fn run_interface(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>) {
     interface.exit();
 }
 
-fn create_domain<S: Into<String>>(miner: Arc<Mutex<Miner>>, name: S, data: S, keystore: &Keystore) {
+fn create_domain<S: Into<String>>(context: Arc<Mutex<Context>>, miner: Arc<Mutex<Miner>>, name: S, data: S, keystore: &Keystore) {
     let name = name.into();
     info!("Generating domain or zone {}", name);
+    if context.lock().unwrap().iana.has_zone(&name) {
+        error!("Unable to mine IANA zone {}!", &name);
+        return;
+    }
     //let tags_vector: Vec<String> = tags.into().trim().split(",").map(|s| s.trim()).map(String::from).collect();
     let transaction = Transaction::from_str(name.into(), "dns".into(), data.into(), keystore.get_public().clone());
     let block = Block::new(Some(transaction), keystore.get_public(), Bytes::default());
-    let mut miner_guard = miner.lock().unwrap();
-    miner_guard.add_block(block);
+    miner.lock().unwrap().add_block(block);
 }
 
 #[derive(Deserialize)]