diff --git a/Cargo.lock b/Cargo.lock
index 7e8a115..8063ceb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -40,6 +40,35 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "bumpalo"
+version = "3.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5dd9dc738b7a8311c7ade152424974d8115f2cdad61e8dab8dac9f2362298510"
+
+[[package]]
+name = "bytecheck"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0caa33a2c0edca0419d15ac723dff03f1956f7978329b1e3b5fdaaaed9d3ca8b"
+dependencies = [
+ "bytecheck_derive",
+ "ptr_meta",
+ "rancor",
+ "simdutf8",
+]
+
+[[package]]
+name = "bytecheck_derive"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89385e82b5d1821d2219e0b095efa2cc1f246cbf99080f3be46a1a85c0d392d9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "bytes"
 version = "1.11.0"
@@ -156,6 +185,12 @@ dependencies = [
  "crypto-common 0.2.0-rc.9",
 ]
 
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -166,6 +201,12 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+
 [[package]]
 name = "hex"
 version = "0.4.3"
@@ -181,6 +222,26 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "indexmap"
+version = "2.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ad4bb2b565bca0645f4d68c5c9af97fba094e9791da685bf83cb5f3ce74acf2"
+dependencies = [
+ "equivalent",
+ "hashbrown",
+]
+
+[[package]]
+name = "js-sys"
+version = "0.3.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "464a3709c7f55f1f721e5389aa6ea4e3bc6aba669353300af094b29ffbdde1d8"
+dependencies = [
+ "once_cell",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.179"
@@ -193,6 +254,26 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f9fbbcab51052fe104eb5e5d351cf728d30a5be1fe14d9be8a3b097481fb97de"
 
+[[package]]
+name = "munge"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e17401f259eba956ca16491461b6e8f72913a0a114e39736ce404410f915a0c"
+dependencies = [
+ "munge_macro",
+]
+
+[[package]]
+name = "munge_macro"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4568f25ccbd45ab5d5603dc34318c1ec56b117531781260002151b8530a9f931"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -202,6 +283,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.21.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+
 [[package]]
 name = "pem-rfc7468"
 version = "1.0.0"
@@ -246,12 +333,34 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "ptr_meta"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b9a0cf95a1196af61d4f1cbdab967179516d9a4a4312af1f31948f8f6224a79"
+dependencies = [
+ "ptr_meta_derive",
+]
+
+[[package]]
+name = "ptr_meta_derive"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7347867d0a7e1208d93b46767be83e2b8f978c3dad35f775ac8d8847551d6fe1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "pyroxene"
 version = "0.1.0"
 dependencies = [
+ "rkyv",
  "rsa",
  "sha256",
+ "socket2",
 ]
 
 [[package]]
@@ -263,12 +372,60 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rancor"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a063ea72381527c2a0561da9c80000ef822bdd7c3241b1cc1b12100e3df081ee"
+dependencies = [
+ "ptr_meta",
+]
+
 [[package]]
 name = "rand_core"
 version = "0.10.0-rc-3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f66ee92bc15280519ef199a274fe0cafff4245d31bc39aaa31c011ad56cb1f05"
 
+[[package]]
+name = "rend"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cadadef317c2f20755a64d7fdc48f9e7178ee6b0e1f7fce33fa60f1d68a276e6"
+dependencies = [
+ "bytecheck",
+]
+
+[[package]]
+name = "rkyv"
+version = "0.8.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2e88acca7157d83d789836a3987dafc12bc3d88a050e54b8fe9ea4aaa29d20"
+dependencies = [
+ "bytecheck",
+ "bytes",
+ "hashbrown",
+ "indexmap",
+ "munge",
+ "ptr_meta",
+ "rancor",
+ "rend",
+ "rkyv_derive",
+ "tinyvec",
+ "uuid",
+]
+
+[[package]]
+name = "rkyv_derive"
+version = "0.8.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f6dffea3c91fa91a3c0fc8a061b0e27fef25c6304728038a6d6bcb1c58ba9bd"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "rsa"
 version = "0.10.0-rc.11"
@@ -287,6 +444,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rustversion"
+version = "1.0.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
+
 [[package]]
 name = "serde"
 version = "1.0.228"
@@ -360,6 +523,22 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "simdutf8"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
+
+[[package]]
+name = "socket2"
+version = "0.5.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e22376abed350d73dd1cd119b57ffccad95b4e585a7cda43e286245ce23c0678"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
 [[package]]
 name = "spki"
 version = "0.8.0-rc.4"
@@ -381,6 +560,21 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "tinyvec"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa5fdc3bce6191a1dbc8c02d5c8bffcf557bafa17c124c5264a458f1b0613fa"
+dependencies = [
+ "tinyvec_macros",
+]
+
+[[package]]
+name = "tinyvec_macros"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
+
 [[package]]
 name = "tokio"
 version = "1.49.0"
@@ -403,12 +597,140 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
+[[package]]
+name = "uuid"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2e054861b4bd027cd373e18e8d8d8e6548085000e41290d95ce0c373a654b4a"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d759f433fa64a2d763d1340820e46e111a7a5ab75f993d1852d70b03dbb80fd"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "rustversion",
+ "wasm-bindgen-macro",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48cb0d2638f8baedbc542ed444afc0644a29166f1595371af4fecf8ce1e7eeb3"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cefb59d5cd5f92d9dcf80e4683949f15ca4b511f4ac0a6e14d4e1ac60c6ecd40"
+dependencies = [
+ "bumpalo",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cbc538057e648b67f72a982e708d485b2efa771e1ac05fec311f9f63e5800db4"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
 [[package]]
 name = "zeroize"
 version = "1.8.2"
diff --git a/Cargo.toml b/Cargo.toml
index 0b857c5..b34c9a7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,5 +5,7 @@ edition = "2024"
 
 [dependencies]
 rsa = "0.10.0-rc.11"
-sha2 = "0.11.0-rc.3"
-rand = "0.10.0-rc.6"
\ No newline at end of file
+sha2 = "0.10.9"
+socket2 = "0.5"
+rkyv = "0.8.13"
+rand = "0.10.0-rc.6"
diff --git a/src/block/block.rs b/src/block/block.rs
new file mode 100644
index 0000000..f282e9f
--- /dev/null
+++ b/src/block/block.rs
@@ -0,0 +1,11 @@
+use crate::block::transaction::Transaction;
+
+pub struct BlockHeader {
+    prev_hash: [u8; 32],
+    nonce: u64,
+    merkle_root: [u8; 32]
+}
+pub struct Block{
+    block_header: BlockHeader,
+    txs: Vec<Transaction>
+}
\ No newline at end of file
diff --git a/src/block/mod.rs b/src/block/mod.rs
new file mode 100644
index 0000000..b87e751
--- /dev/null
+++ b/src/block/mod.rs
@@ -0,0 +1,6 @@
+pub mod block;
+pub mod transaction{
+    pub struct Transaction{
+
+    }
+}
\ No newline at end of file
diff --git a/src/block.rs b/src/block/transaction.rs
similarity index 100%
rename from src/block.rs
rename to src/block/transaction.rs
diff --git a/src/network.rs b/src/network.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/network/mod.rs b/src/network/mod.rs
new file mode 100644
index 0000000..a8f5fec
--- /dev/null
+++ b/src/network/mod.rs
@@ -0,0 +1,78 @@
+use socket2::{Domain, Protocol, Socket, Type};
+use std::io::Result;
+use std::net::{SocketAddr, SocketAddrV4, UdpSocket};
+
+mod protocol;
+
+pub const PORT: u16 = 1200;
+
+pub struct UdpBroadcast {
+    socket: UdpSocket,
+    target: SocketAddr,
+}
+
+impl UdpBroadcast {
+    pub fn new() -> Result<Self> {
+        Self::with_port(PORT, PORT)
+    }
+
+    pub fn with_port(send: u16, receive: u16) -> Result<Self> {
+        let socket = Socket::new(Domain::IPV4, Type::DGRAM, Some(Protocol::UDP))?;
+        socket.set_broadcast(true)?;
+        socket.set_reuse_address(true)?;
+
+        let addr: SocketAddr = ([0, 0, 0, 0], receive).into(); // 0.0.0.0 != 192.168.x.x.. 미래의 나, 해결해라!
+        socket.bind(&addr.into())?;
+
+        let socket: UdpSocket = socket.into();
+
+        Ok(Self {
+            socket,
+            target: ([255, 255, 255, 255], send).into(), // 브로드캐스트 주소 바꿀 것
+        })
+    }
+
+    pub fn send(&self, data: &[u8]) -> Result<usize> {
+        self.socket.send_to(data, self.target)
+    }
+
+    pub fn recv(&self, buf: &mut [u8]) -> Result<(usize, SocketAddr)> {
+        self.socket.recv_from(buf)
+    }
+
+    pub fn is_self(&self, addr: SocketAddr) -> bool {
+        addr == self.target
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::thread;
+    use std::time::Duration;
+    use crate::network::UdpBroadcast;
+
+    #[test]
+    fn test_broadcast() {
+        let node1 = UdpBroadcast::new().unwrap();
+        let node2 = UdpBroadcast::new().unwrap();
+        let data: [u8; 4] = [0x43, 0x55, 0x54, 0x45];
+        let mut receive_buffer = [0u8; 4];
+
+        let receiver = thread::scope(|scope| {
+            let result = scope.spawn(|| {
+                thread::sleep(Duration::from_secs(1));
+                node2.recv(&mut receive_buffer).unwrap()
+            });
+            scope.spawn(|| {
+                node1.send(&data).unwrap();
+            });
+            result.join().unwrap()
+        });
+        let (receive_count, sender_address) = receiver;
+
+        assert_eq!(receive_count, data.len());
+        assert_eq!(receive_buffer, data);
+
+    }
+
+}
\ No newline at end of file
diff --git a/src/network/protocol.rs b/src/network/protocol.rs
new file mode 100644
index 0000000..d092c38
--- /dev/null
+++ b/src/network/protocol.rs
@@ -0,0 +1,87 @@
+
+use rkyv::{Archive, Deserialize, Serialize};
+use std::net::Ipv4Addr;
+
+#[derive(Archive, Deserialize, Serialize, Debug, PartialEq, Clone)]
+#[rkyv(
+    compare(PartialEq),
+    derive(Debug),
+)]
+pub struct Packet {
+    pub sender_ip: [u8; 4],
+}
+
+impl Packet {
+    pub fn new(sender: Ipv4Addr) -> Self {
+        Self {
+            sender_ip: sender.octets(),
+        }
+    }
+
+    pub fn sender(&self) -> Ipv4Addr {
+        Ipv4Addr::from(self.sender_ip)
+    }
+}
+
+impl ArchivedPacket {
+    pub fn sender(&self) -> Ipv4Addr {
+        Ipv4Addr::new(
+            self.sender_ip[0],
+            self.sender_ip[1],
+            self.sender_ip[2],
+            self.sender_ip[3],
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::network::UdpBroadcast;
+    use std::net::Ipv4Addr;
+    use std::thread;
+    use std::time::Duration;
+
+    #[test]
+    fn test_packet_broadcast() {
+        let node1 = UdpBroadcast::with_port(1201, 1201).unwrap();
+        let node2 = UdpBroadcast::with_port(1201, 1201).unwrap();
+
+        // 보낼 패킷
+        let packet = Packet::new(Ipv4Addr::new(192, 168, 0, 100));
+
+        let serialized = rkyv::to_bytes::<rkyv::rancor::Error>(&packet).unwrap();
+
+        let mut receive_buffer = [0u8; 1024]; // 1KB 버퍼 재사용
+
+        let receiver = thread::scope(|scope| {
+            let result = scope.spawn(|| {
+                thread::sleep(Duration::from_millis(100));
+                let (size, addr) = node2.recv(&mut receive_buffer).unwrap();
+                (size, addr)
+            });
+
+            scope.spawn(|| {
+                thread::sleep(Duration::from_millis(50));
+                node1.send(&serialized).unwrap();
+            });
+
+            result.join().unwrap()
+        });
+
+        let (received_size, _sender_addr) = receiver;
+
+
+        let valid_data = &receive_buffer[..received_size];
+
+
+        let archived = rkyv::access::<ArchivedPacket, rkyv::rancor::Error>(valid_data).unwrap();
+
+        assert_eq!(archived.sender(), packet.sender());
+        assert_eq!(archived.sender(), Ipv4Addr::new(192, 168, 0, 100));
+
+        // 역직렬화
+        let deserialized: Packet = rkyv::deserialize::<Packet, rkyv::rancor::Error>(archived).unwrap();
+        assert_eq!(deserialized, packet);
+    }
+}
\ No newline at end of file