diff --git a/alfis.cfg b/alfis.cfg
index a254567..4de36d3 100644
--- a/alfis.cfg
+++ b/alfis.cfg
@@ -1,7 +1,8 @@
 {
     "chain_name": "test",
-    "version_flags": 0,
-    "key_file": "default.key",
+    "origin": "",
+    "version": 0,
+    "key_file": "default3.key",
     "listen": "127.0.0.1:4244",
     "public": true,
     "peers": [
diff --git a/src/blockchain/block.rs b/src/blockchain/block.rs
index 191655c..5a4f0ef 100644
--- a/src/blockchain/block.rs
+++ b/src/blockchain/block.rs
@@ -17,8 +17,7 @@ use crate::Transaction;
 pub struct Block {
     pub index: u64,
     pub timestamp: i64,
-    pub chain_name: String,
-    pub version_flags: u32,
+    pub version: u32,
     pub difficulty: usize,
     pub random: u32,
     pub nonce: u64,
@@ -31,12 +30,11 @@ pub struct Block {
 }
 
 impl Block {
-    pub fn new(index: u64, timestamp: i64, chain_name: &str, version_flags: u32, prev_block_hash: Bytes, transaction: Option<Transaction>) -> Self {
+    pub fn new(index: u64, timestamp: i64, version: u32, prev_block_hash: Bytes, transaction: Option<Transaction>) -> Self {
         Block {
             index,
             timestamp,
-            chain_name: chain_name.to_owned(),
-            version_flags,
+            version,
             // TODO make difficulty parameter
             difficulty: 20,
             random: 0,
@@ -47,12 +45,11 @@ impl Block {
         }
     }
 
-    pub fn from_all_params(index: u64, timestamp: i64, chain_name: &str, version_flags: u32, difficulty: usize, random: u32, nonce: u64, prev_block_hash: Bytes, hash: Bytes, transaction: Option<Transaction>) -> Self {
+    pub fn from_all_params(index: u64, timestamp: i64, version: u32, difficulty: usize, random: u32, nonce: u64, prev_block_hash: Bytes, hash: Bytes, transaction: Option<Transaction>) -> Self {
         Block {
             index,
             timestamp,
-            chain_name: chain_name.to_owned(),
-            version_flags,
+            version,
             difficulty,
             random,
             nonce,
diff --git a/src/blockchain/blockchain.rs b/src/blockchain/blockchain.rs
index a6184cd..e5e0b2b 100644
--- a/src/blockchain/blockchain.rs
+++ b/src/blockchain/blockchain.rs
@@ -6,17 +6,17 @@ use crate::{Block, Bytes, Keystore, Transaction};
 const DB_NAME: &str = "blockchain.db";
 
 pub struct Blockchain {
-    pub chain_name: String,
-    pub version_flags: u32,
+    origin: String,
+    pub version: u32,
     pub blocks: Vec<Block>,
     last_block: Option<Block>,
     db: Connection,
 }
 
 impl Blockchain {
-    pub fn new(chain_name: &str, version_flags: u32) -> Self {
+    pub fn new(origin: String, version: u32) -> Self {
         let db = sqlite::open(DB_NAME).expect("Unable to open blockchain DB");
-        let mut blockchain = Blockchain{ chain_name: chain_name.to_owned(), version_flags, blocks: Vec::new(), last_block: None, db};
+        let mut blockchain = Blockchain{ origin, version, blocks: Vec::new(), last_block: None, db};
         blockchain.init_db();
         blockchain
     }
@@ -30,12 +30,11 @@ impl Blockchain {
                         None => { println!("Something wrong with block in DB!"); }
                         Some(block) => {
                             println!("Loaded last block: {:?}", &block);
-                            self.chain_name = block.chain_name.clone();
-                            self.version_flags = block.version_flags;
+                            self.version = block.version;
                             self.last_block = Some(block);
                         }
                     }
-                    println!("Loaded from DB: chain_name = {}, version_flags = {}", self.chain_name, self.version_flags);
+                    println!("Blockchain version from DB = {}", self.version);
                 }
             }
             Err(_) => {
@@ -44,8 +43,7 @@ impl Blockchain {
                     CREATE TABLE blocks (
                                          'id' BIGINT,
                                          'timestamp' BIGINT,
-                                         'chain_name' TEXT,
-                                         'version_flags' TEXT,
+                                         'version' TEXT,
                                          'difficulty' INTEGER,
                                          'random' INTEGER,
                                          'nonce' INTEGER,
@@ -54,7 +52,7 @@ impl Blockchain {
                                          'hash' BINARY
                                          );
                     CREATE INDEX block_index ON blocks (id);
-                    CREATE TABLE transactions (id INTEGER PRIMARY KEY AUTOINCREMENT, identity BINARY, method TEXT, data TEXT, pub_key BINARY, signature BINARY);
+                    CREATE TABLE transactions (id INTEGER PRIMARY KEY AUTOINCREMENT, identity BINARY, confirmation BINARY, method TEXT, data TEXT, pub_key BINARY, signature BINARY);
                     CREATE INDEX ids ON transactions (identity);"
                 ).expect("Error creating blocks table");
             }
@@ -71,24 +69,23 @@ impl Blockchain {
             {
                 // Adding block to DB
                 let mut statement = self.db.prepare("INSERT INTO blocks (\
-                    id, timestamp, chain_name, version_flags, difficulty,\
-                    random, nonce, 'transaction', prev_block_hash, hash)\
-                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?);").unwrap();
+                    id, timestamp, version, difficulty, random,\
+                    nonce, 'transaction', prev_block_hash, hash)\
+                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?);").unwrap();
                 statement.bind(1, block.index as i64);
                 statement.bind(2, block.timestamp as i64);
-                statement.bind(3, block.chain_name.as_ref() as &str);
-                statement.bind(4, block.version_flags as i64);
-                statement.bind(5, block.difficulty as i64);
-                statement.bind(6, block.random as i64);
-                statement.bind(7, block.nonce as i64);
+                statement.bind(3, block.version as i64);
+                statement.bind(4, block.difficulty as i64);
+                statement.bind(5, block.random as i64);
+                statement.bind(6, block.nonce as i64);
                 match &transaction {
-                    None => { statement.bind(8, ""); }
+                    None => { statement.bind(7, ""); }
                     Some(transaction) => {
-                        statement.bind(8, transaction.to_string().as_ref() as &str);
+                        statement.bind(7, transaction.to_string().as_ref() as &str);
                     }
                 }
-                statement.bind(9, block.prev_block_hash.as_bytes());
-                statement.bind(10, block.hash.as_bytes());
+                statement.bind(8, block.prev_block_hash.as_bytes());
+                statement.bind(9, block.hash.as_bytes());
                 statement.next().expect("Error adding block to DB");
             }
 
@@ -104,12 +101,13 @@ impl Blockchain {
     }
 
     fn add_transaction(&mut self, t: &Transaction) {
-        let mut statement = self.db.prepare("INSERT INTO transactions (identity, method, data, pub_key, signature) VALUES (?, ?, ?, ?, ?)").unwrap();
+        let mut statement = self.db.prepare("INSERT INTO transactions (identity, confirmation, method, data, pub_key, signature) VALUES (?, ?, ?, ?, ?, ?)").unwrap();
         statement.bind(1, t.identity.as_bytes());
-        statement.bind(2, t.method.as_ref() as &str);
-        statement.bind(3, t.data.as_ref() as &str);
-        statement.bind(4, t.pub_key.as_bytes());
-        statement.bind(5, t.signature.as_bytes());
+        statement.bind(2, t.confirmation.as_bytes());
+        statement.bind(3, t.method.as_ref() as &str);
+        statement.bind(4, t.data.as_ref() as &str);
+        statement.bind(5, t.pub_key.as_bytes());
+        statement.bind(6, t.signature.as_bytes());
         statement.next().expect("Error adding transaction to DB");
     }
 
@@ -212,15 +210,14 @@ impl Blockchain {
     fn get_block_from_statement(statement: &mut Statement) -> Option<Block> {
         let index = statement.read::<i64>(0).unwrap() as u64;
         let timestamp = statement.read::<i64>(1).unwrap();
-        let chain_name = statement.read::<String>(2).unwrap();
-        let version_flags = statement.read::<i64>(3).unwrap() as u32;
-        let difficulty = statement.read::<i64>(4).unwrap() as usize;
-        let random = statement.read::<i64>(5).unwrap() as u32;
-        let nonce = statement.read::<i64>(6).unwrap() as u64;
-        let transaction = Transaction::from_json(&statement.read::<String>(7).unwrap());
-        let prev_block_hash = Bytes::from_bytes(statement.read::<Vec<u8>>(8).unwrap().as_slice());
-        let hash = Bytes::from_bytes(statement.read::<Vec<u8>>(9).unwrap().as_slice());
-        Some(Block::from_all_params(index, timestamp, &chain_name, version_flags, difficulty, random, nonce, prev_block_hash, hash, transaction))
+        let version = statement.read::<i64>(2).unwrap() as u32;
+        let difficulty = statement.read::<i64>(3).unwrap() as usize;
+        let random = statement.read::<i64>(4).unwrap() as u32;
+        let nonce = statement.read::<i64>(5).unwrap() as u64;
+        let transaction = Transaction::from_json(&statement.read::<String>(6).unwrap());
+        let prev_block_hash = Bytes::from_bytes(statement.read::<Vec<u8>>(7).unwrap().as_slice());
+        let hash = Bytes::from_bytes(statement.read::<Vec<u8>>(8).unwrap().as_slice());
+        Some(Block::from_all_params(index, timestamp, version, difficulty, random, nonce, prev_block_hash, hash, transaction))
     }
 
     pub fn check_block_hash(block: &Block) -> bool {
diff --git a/src/blockchain/transaction.rs b/src/blockchain/transaction.rs
index 04070cb..8d623e7 100644
--- a/src/blockchain/transaction.rs
+++ b/src/blockchain/transaction.rs
@@ -12,6 +12,7 @@ use crypto::digest::Digest;
 #[derive(Clone, Deserialize, PartialEq)]
 pub struct Transaction {
     pub identity: Bytes,
+    pub confirmation: Bytes,
     pub method: String,
     pub data: String,
     pub pub_key: Bytes,
@@ -20,12 +21,13 @@ pub struct Transaction {
 
 impl Transaction {
     pub fn from_str(identity: String, method: String, data: String, pub_key: Bytes) -> Self {
-        let bytes = Self::hash_identity(&identity);
-        return Self::new(bytes, method, data, pub_key);
+        let hash = Self::hash_identity(&identity);
+        let confirmation = Self::hash_with_key(&identity, &pub_key);
+        return Self::new(hash, confirmation, method, data, pub_key);
     }
 
-    pub fn new(identity: Bytes, method: String, data: String, pub_key: Bytes) -> Self {
-        Transaction { identity, method, data, pub_key, signature: Bytes::zero64() }
+    pub fn new(identity: Bytes, confirmation: Bytes, method: String, data: String, pub_key: Bytes) -> Self {
+        Transaction { identity, confirmation, method, data, pub_key, signature: Bytes::zero64() }
     }
 
     pub fn from_json(json: &str) -> Option<Self> {
@@ -56,12 +58,22 @@ impl Transaction {
         digest.result(&mut buf);
         Bytes::from_bytes(&buf)
     }
+
+    pub fn hash_with_key(identity: &str, key: &Bytes) -> Bytes {
+        let mut buf: [u8; 32] = [0; 32];
+        let mut digest = Sha256::new();
+        digest.input_str(identity);
+        digest.input(key.as_bytes());
+        digest.result(&mut buf);
+        Bytes::from_bytes(&buf)
+    }
 }
 
 impl fmt::Debug for Transaction {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         fmt.debug_struct("Transaction")
             .field("identity", &self.identity)
+            .field("confirmation", &self.confirmation)
             .field("method", &self.method)
             .field("data", &self.data)
             .field("pub", &&self.pub_key)
@@ -71,10 +83,10 @@ impl fmt::Debug for Transaction {
 }
 
 impl Serialize for Transaction {
-    fn serialize<S>(&self, serializer: S) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where
-        S: Serializer {
-        let mut structure = serializer.serialize_struct("Transaction", 3).unwrap();
+    fn serialize<S>(&self, serializer: S) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where S: Serializer {
+        let mut structure = serializer.serialize_struct("Transaction", 6).unwrap();
         structure.serialize_field("identity", &self.identity);
+        structure.serialize_field("confirmation", &self.confirmation);
         structure.serialize_field("method", &self.method);
         structure.serialize_field("data", &self.data);
         structure.serialize_field("pub_key", &self.pub_key);
diff --git a/src/context.rs b/src/context.rs
index c1bf4e0..4fe0354 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,4 +1,4 @@
-use crate::{Keystore, Blockchain, Bus};
+use crate::{Keystore, Blockchain, Bus, Bytes};
 use crate::event::Event;
 use std::collections::HashMap;
 use serde::{Serialize, Deserialize, Serializer, Deserializer};
@@ -7,9 +7,9 @@ use std::fs::File;
 use std::io::Read;
 
 pub struct Context {
-    pub(crate) settings: Settings,
-    pub(crate) keystore: Keystore,
-    pub(crate) blockchain: Blockchain,
+    pub settings: Settings,
+    pub keystore: Keystore,
+    pub blockchain: Blockchain,
     pub bus: Bus<Event>,
 }
 
@@ -48,8 +48,8 @@ impl Context {
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Settings {
-    pub chain_name: String,
-    pub version_flags: u32,
+    pub origin: String,
+    pub version: u32,
     pub key_file: String,
     pub listen: String,
     pub public: bool,
@@ -76,4 +76,9 @@ impl Settings {
             Err(..) => None
         }
     }
+
+    pub fn get_origin(&self) -> Bytes {
+        let origin = crate::from_hex(&self.origin).expect("Wrong origin in settings");
+        Bytes::from_bytes(origin.as_slice())
+    }
 }
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index e696749..51249b3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -31,7 +31,7 @@ fn main() {
         None => { generate_key(KEYSTORE_DIFFICULTY, Arc::new(AtomicBool::new(true))).expect("Could not load or generate keypair") }
         Some(keystore) => { keystore }
     };
-    let blockchain: Blockchain = Blockchain::new(&settings.chain_name, settings.version_flags);
+    let blockchain: Blockchain = Blockchain::new(settings.origin.clone(), settings.version);
     let context: Arc<Mutex<Context>> = Arc::new(Mutex::new(Context::new(settings, keystore, blockchain)));
 
     let mut miner_obj = Miner::new(context.clone());
@@ -46,11 +46,14 @@ fn main() {
 }
 
 fn create_genesis_if_needed(context: &Arc<Mutex<Context>>, miner: &Arc<Mutex<Miner>>) {
-    // TODO check settings and if there is no mention of bootstrap nodes, generate genesis block
-    let context_guard = context.lock().unwrap();
-    if context_guard.get_blockchain().last_block().is_none() {
+    // If there is no origin in settings and no blockchain in DB, generate genesis block
+    let context = context.lock().unwrap();
+    // TODO compare first block's hash to origin
+    let last_block = context.get_blockchain().last_block();
+    let origin = context.settings.origin.clone();
+    if origin.eq("") && last_block.is_none() {
         // If blockchain is empty, we are going to mine a Genesis block
-        create_genesis(miner.clone(), GENESIS_ZONE, &context_guard.get_keystore(), GENESIS_ZONE_DIFFICULTY);
+        create_genesis(miner.clone(), GENESIS_ZONE, &context.get_keystore(), GENESIS_ZONE_DIFFICULTY);
     }
 }
 
diff --git a/src/miner.rs b/src/miner.rs
index b8491a9..2431431 100644
--- a/src/miner.rs
+++ b/src/miner.rs
@@ -14,8 +14,7 @@ use crate::event::Event;
 pub struct Miner {
     context: Arc<Mutex<Context>>,
     keystore: Keystore,
-    chain_name: String,
-    version_flags: u32,
+    version: u32,
     transactions: Arc<Mutex<Vec<Transaction>>>,
     last_block: Option<Block>,
     running: Arc<AtomicBool>,
@@ -29,8 +28,7 @@ impl Miner {
         Miner {
             context: context.clone(),
             keystore: c.keystore.clone(),
-            chain_name: c.settings.chain_name.clone(),
-            version_flags: c.settings.version_flags,
+            version: c.settings.version,
             transactions: Arc::new(Mutex::new(Vec::new())),
             last_block: c.blockchain.blocks.last().cloned(),
             running: Arc::new(AtomicBool::new(false)),
@@ -93,13 +91,11 @@ impl Miner {
 
     fn mine_internal(context: Arc<Mutex<Context>>, transactions: Arc<Mutex<Vec<Transaction>>>, mut transaction: Transaction, mining: Arc<AtomicBool>, cond_var: Arc<Condvar>) {
         let mut last_block_time = 0i64;
-        let mut chain_name= String::new();
-        let mut version_flags= 0u32;
+        let mut version= 0u32;
         {
             let mut c = context.lock().unwrap();
             c.bus.post(Event::MinerStarted);
-            chain_name = c.settings.chain_name.clone();
-            version_flags = c.settings.version_flags;
+            version = c.settings.version;
         }
         let block = {
             if transaction.signature.is_zero() {
@@ -115,12 +111,12 @@ impl Miner {
                 None => {
                     println!("Mining genesis block");
                     // Creating a block with that signed transaction
-                    Block::new(0, Utc::now().timestamp(), &chain_name, version_flags, Bytes::zero32(), Some(transaction.clone()))
+                    Block::new(0, Utc::now().timestamp(), version, Bytes::zero32(), Some(transaction.clone()))
                 },
                 Some(block) => {
                     last_block_time = block.timestamp;
                     // Creating a block with that signed transaction
-                    Block::new(block.index + 1, Utc::now().timestamp(), &chain_name, version_flags, block.hash.clone(), Some(transaction.clone()))
+                    Block::new(block.index + 1, Utc::now().timestamp(), version, block.hash.clone(), Some(transaction.clone()))
                 },
             }
         };
diff --git a/src/p2p/message.rs b/src/p2p/message.rs
index 3733f99..c5d841f 100644
--- a/src/p2p/message.rs
+++ b/src/p2p/message.rs
@@ -7,8 +7,8 @@ use crate::p2p::peer::Peer;
 #[derive(Debug, Serialize, Deserialize)]
 pub enum Message {
     Error,
-    Hand { chain: String, version: u32, public: bool },
-    Shake { ok: bool, height: u64 },
+    Hand { origin: String, version: u32, public: bool },
+    Shake { origin: String, version: u32, ok: bool, height: u64 },
     Ping { height: u64 },
     Pong { height: u64 },
     GetPeers,
@@ -26,12 +26,12 @@ impl Message {
         }
     }
 
-    pub fn hand(chain: &str, version: u32, public: bool) -> Self {
-        Message::Hand { chain: chain.to_owned(), version, public }
+    pub fn hand(origin: &str, version: u32, public: bool) -> Self {
+        Message::Hand { origin: origin.to_owned(), version, public }
     }
 
-    pub fn shake(ok: bool, height: u64) -> Self {
-        Message::Shake { ok, height }
+    pub fn shake(origin: &str, version: u32, ok: bool, height: u64) -> Self {
+        Message::Shake { origin: origin.to_owned(), version, ok, height }
     }
 
     pub fn ping(height: u64) -> Self {
diff --git a/src/p2p/network.rs b/src/p2p/network.rs
index 482cdb0..553b22d 100644
--- a/src/p2p/network.rs
+++ b/src/p2p/network.rs
@@ -176,7 +176,7 @@ fn handle_connection_event(context: Arc<Mutex<Context>>, peers: &mut Peers, regi
                         println!("Sending hello to socket {}", event.token().0);
                         let data: String = {
                             let mut c = context.lock().unwrap();
-                            let message = Message::hand(&c.settings.chain_name, c.settings.version_flags, c.settings.public);
+                            let message = Message::hand(&c.settings.origin, c.settings.version, c.settings.public);
                             serde_json::to_string(&message).unwrap()
                         };
                         send_message(peer.get_stream(), &data.into_bytes());
@@ -255,17 +255,18 @@ fn handle_message(context: Arc<Mutex<Context>>, message: Message, peers: &mut Pe
         context.blockchain.height()
     };
     match message {
-        Message::Hand { chain, version, public } => {
+        Message::Hand { origin: origin, version, public } => {
             let context = context.lock().unwrap();
-            if chain == context.settings.chain_name && version == context.settings.version_flags {
+            if origin == context.settings.origin && version == context.settings.version {
                 let mut peer = peers.get_mut_peer(token).unwrap();
                 peer.set_public(public);
-                State::message(Message::shake(true, context.blockchain.height()))
+                State::message(Message::shake(&context.settings.origin, context.settings.version, true, context.blockchain.height()))
             } else {
                 State::Error
             }
         }
-        Message::Shake { ok, height } => {
+        Message::Shake { origin, version, ok, height } => {
+            // TODO check origin and version for compatibility
             if ok {
                 if height > my_height {
                     State::message(Message::GetBlock { index: my_height + 1u64 })