diff --git a/Cargo.lock b/Cargo.lock
index a23dd5b..2a42ba4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -163,6 +163,7 @@ dependencies = [
 name = "messaging"
 version = "0.1.0"
 dependencies = [
+ "cryptography",
  "process",
  "versioning",
 ]
diff --git a/libraries/messaging/Cargo.toml b/libraries/messaging/Cargo.toml
new file mode 100644
index 0000000..d2225d5
--- /dev/null
+++ b/libraries/messaging/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "messaging"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+versioning = { path = "../versioning" }
+process = { path = "../process" }
+cryptography = { path = "../cryptography" }
diff --git a/libraries/messaging/src/lib.rs b/libraries/messaging/src/lib.rs
new file mode 100644
index 0000000..98ccdce
--- /dev/null
+++ b/libraries/messaging/src/lib.rs
@@ -0,0 +1,49 @@
+#![no_std]
+#[macro_use]
+extern crate alloc;
+
+use alloc::vec::Vec;
+use cryptography::hashing::checksum;
+use process::PID;
+use versioning::Version;
+
+pub const VERSION: Version = Version::new(0, 1, 0);
+
+#[repr(C)]
+pub struct Message {
+    src: PID,         // bytes 0-3
+    dest: PID,        // bytes 4-7
+    version: Version, // bytes 8-10
+    checksum: u64,    // bytes 11-19
+    length: usize,    // bytes 20-23
+    timestamp: u64,   // bytes 24-31
+
+    body: Vec<u8>,
+}
+impl Message {
+    pub fn set_checksum(&mut self) {
+        self.checksum = self.compute_body_checksum()
+    }
+
+    fn compute_body_checksum(&mut self) -> u64 {
+        checksum(&self.body)
+    }
+}
+
+#[test]
+fn test_checksum() {
+    let mut message = Message {
+        src: 123,
+        dest: 456,
+        version: Version::new(0, 1, 0),
+        checksum: 0,
+        timestamp: 0,
+        length: 5,
+        body: vec![1, 2],
+    };
+
+    message.set_checksum();
+
+    assert_eq!(message.checksum, 3);
+    assert_ne!(message.checksum, 1)
+}