diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1f7acfa..d9eddb7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -16,11 +16,17 @@ jobs:
         build: [macos, windows, linux]
         include:
           - build: linux
+            rustflags: ""
             target-bin: 'cusf_launcher.x86_64'
+            target-triple: x86_64-unknown-linux-gnu
           - build: macos
+            rustflags: ""
             target-bin: 'cusf_launcher.dmg'
+            target-triple: x86_64-apple-darwin
           - build: windows
+            rustflags: "-C linker=/usr/bin/x86_64-w64-mingw32-gcc"
             target-bin: 'cusf_launcher.exe'
+            target-triple: x86_64-pc-windows-gnu
 
     steps:
       - uses: actions/checkout@v3
@@ -34,6 +40,16 @@ jobs:
       - name: Verify Setup
         run: godot --version
 
+      - name: Install latest stable Rust toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: stable
+          target: ${{ matrix.target-triple }}
+      
+      - name: Install mingw-w64
+        run: sudo apt install mingw-w64
+        if: ${{ matrix.target-triple == 'x86_64-pc-windows-gnu' }}
+
       - name: Import certificate to Keychain
         if: ${{ matrix.build == 'macos' }}
         run: |
@@ -61,6 +77,14 @@ jobs:
       - name: Initialize godot cache
         run: python3 .github/scripts/godot_ci_cache.py
 
+      - name: Build rust extensions
+        run: |
+          pushd cusf_launcher_crypto
+          cargo build --release --target ${{ matrix.target-triple }}
+          popd
+        env:
+          RUSTFLAGS: ${{ matrix.rustflags }}
+
       - name: Export build
         run: |
           name="${{fromJSON('{"windows": "Windows", "macos": "Mac", "linux": "Linux"}')[matrix.build] }}"
diff --git a/README.md b/README.md
index 5b43d3f..444c968 100644
--- a/README.md
+++ b/README.md
@@ -1,21 +1,34 @@
 # cusf_launcher
 
-Requirements:
-Godot v4.3 :
-https://github.com/godotengine/godot/releases/tag/4.3-stable
+## Requirements:
+* Godot v4.3 : https://github.com/godotengine/godot/releases/tag/4.3-stable
+* Rust/Cargo : https://rustup.rs/
 
-Command line build instructions:
+If cross-compiling for Windows, mingw-64 is required.
 
-Linux:
+## Command line build instructions:
 
-`godot --headless --path cusf_launcher/ --export-release "Linux" cusf_launcher.x86_64`
+Linux:
+```
+pushd cusf_launcher_crypto
+cargo build --release --target x86_64-unknown-linux-gnu
+popd
+godot --headless --path cusf_launcher/ --export-release "Linux" cusf_launcher.x86_64
+```
 
 Windows:
-
-`godot --headless --path cusf_launcher/ --export-release "Windows" cusf_launcher.exe`
+```
+pushd cusf_launcher_crypto
+RUSTFLAGS="-C linker=/usr/bin/x86_64-w64-mingw32-gcc" cargo build --release --target x86_64-pc-windows-gnu
+popd
+godot --headless --path cusf_launcher/ --export-release "Windows" cusf_launcher.exe
+```
 
 Mac:
-
-`godot --headless --path cusf_launcher/ --export-release "Mac" cusf_launcher.dmg`
-
+```
+pushd cusf_launcher_crypto
+cargo build --release --target x86_64-apple-darwin
+popd
+godot --headless --path cusf_launcher/ --export-release "Mac" cusf_launcher.dmg`
+```
 
diff --git a/cusf_launcher/CusfLauncherCrypto.gdextension b/cusf_launcher/CusfLauncherCrypto.gdextension
new file mode 100644
index 0000000..87e9a10
--- /dev/null
+++ b/cusf_launcher/CusfLauncherCrypto.gdextension
@@ -0,0 +1,14 @@
+[configuration]
+entry_symbol = "gdext_cusf_launcher_crypto_init"
+compatibility_minimum = 4.1
+reloadable = true
+
+[libraries]
+linux.debug.x86_64 =     "res://../cusf_launcher_crypto/target/x86_64-unknown-linux-gnu/debug/libcusf_launcher_crypto.so"
+linux.release.x86_64 =   "res://../cusf_launcher_crypto/target/x86_64-unknown-linux-gnu/release/libcusf_launcher_crypto.so"
+windows.debug.x86_64 =   "res://../cusf_launcher_crypto/target/x86_64-pc-windows-gnu/debug/cusf_launcher_crypto.dll"
+windows.release.x86_64 = "res://../cusf_launcher_crypto/target/x86_64-pc-windows-gnu/release/cusf_launcher_crypto.dll"
+macos.debug =            "res://../cusf_launcher_crypto/target/x86_64-apple-darwin/debug/libcusf_launcher_crypto.dylib"
+macos.release =          "res://../cusf_launcher_crypto/target/x86_64-apple-darwin/release/libcusf_launcher_crypto.dylib"
+macos.debug.arm64 =      "res://../cusf_launcher_crypto/target/aarch64-apple-darwin/debug/libcusf_launcher_crypto.dylib"
+macos.release.arm64 =    "res://../cusf_launcher_crypto/target/aarch64-apple-darwin/release/libcusf_launcher_crypto.dylib"
\ No newline at end of file
diff --git a/cusf_launcher_crypto/.gitignore b/cusf_launcher_crypto/.gitignore
new file mode 100644
index 0000000..c41cc9e
--- /dev/null
+++ b/cusf_launcher_crypto/.gitignore
@@ -0,0 +1 @@
+/target
\ No newline at end of file
diff --git a/cusf_launcher_crypto/Cargo.lock b/cusf_launcher_crypto/Cargo.lock
new file mode 100644
index 0000000..4a95ac0
--- /dev/null
+++ b/cusf_launcher_crypto/Cargo.lock
@@ -0,0 +1,282 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "arrayvec"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
+
+[[package]]
+name = "bitcoin_hashes"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb18c03d0db0247e147a21a6faafd5a7eb851c743db062de72018b6b7e8e4d16"
+dependencies = [
+ "hex-conservative",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "cusf_launcher_crypto"
+version = "0.1.0"
+dependencies = [
+ "bitcoin_hashes",
+ "godot",
+]
+
+[[package]]
+name = "gdextension-api"
+version = "0.2.0"
+source = "git+https://github.com/godot-rust/godot4-prebuilt?branch=releases#6d902e8a6060007f4ab94cd78882247ae2558d96"
+
+[[package]]
+name = "gensym"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "913dce4c5f06c2ea40fc178c06f777ac89fc6b1383e90c254fafb1abe4ba3c82"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "uuid",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "glam"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "779ae4bf7e8421cf91c0b3b64e7e8b40b862fba4d393f59150042de7c4965a94"
+
+[[package]]
+name = "godot"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "godot-core",
+ "godot-macros",
+]
+
+[[package]]
+name = "godot-bindings"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "gdextension-api",
+]
+
+[[package]]
+name = "godot-cell"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+
+[[package]]
+name = "godot-codegen"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "godot-bindings",
+ "heck",
+ "nanoserde",
+ "proc-macro2",
+ "quote",
+ "regex",
+]
+
+[[package]]
+name = "godot-core"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "glam",
+ "godot-bindings",
+ "godot-cell",
+ "godot-codegen",
+ "godot-ffi",
+]
+
+[[package]]
+name = "godot-ffi"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "gensym",
+ "godot-bindings",
+ "godot-codegen",
+ "libc",
+ "paste",
+]
+
+[[package]]
+name = "godot-macros"
+version = "0.1.3"
+source = "git+https://github.com/godot-rust/gdext?branch=master#a0d579900308b87358b646df43c9100b36cc5ba6"
+dependencies = [
+ "godot-bindings",
+ "proc-macro2",
+ "quote",
+ "venial",
+]
+
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
+[[package]]
+name = "hex-conservative"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5313b072ce3c597065a808dbf612c4c8e8590bdbf8b579508bf7a762c5eae6cd"
+dependencies = [
+ "arrayvec",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.161"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9489c2807c139ffd9c1794f4af0ebe86a828db53ecdc7fea2111d0fed085d1"
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "nanoserde"
+version = "0.1.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5de9cf844ab1e25a0353525bd74cb889843a6215fa4a0d156fd446f4857a1b99"
+dependencies = [
+ "nanoserde-derive",
+]
+
+[[package]]
+name = "nanoserde-derive"
+version = "0.1.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e943b2c21337b7e3ec6678500687cdc741b7639ad457f234693352075c082204"
+
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "regex"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "368758f23274712b504848e9d5a6f010445cc8b87a7cdb4d7cbee666c1288da3"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+
+[[package]]
+name = "syn"
+version = "2.0.85"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5023162dfcd14ef8f32034d8bcd4cc5ddc61ef7a247c024a33e24e1f24d21b56"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
+
+[[package]]
+name = "uuid"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8c5f0a0af699448548ad1a2fbf920fb4bee257eae39953ba95cb84891a0446a"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "venial"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6816bc32f30bf8dd1b3adb04de8406c7bf187d2f923bd9e4c0b99365d012613f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+]
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
diff --git a/cusf_launcher_crypto/Cargo.toml b/cusf_launcher_crypto/Cargo.toml
new file mode 100644
index 0000000..bb7e469
--- /dev/null
+++ b/cusf_launcher_crypto/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "cusf_launcher_crypto"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]  # Compile this crate to a dynamic C library.
+
+[dependencies]
+bitcoin_hashes = { version = "0.14.0", default-features = false }
+godot = { git = "https://github.com/godot-rust/gdext", branch = "master" }
\ No newline at end of file
diff --git a/cusf_launcher_crypto/src/lib.rs b/cusf_launcher_crypto/src/lib.rs
new file mode 100644
index 0000000..4db4991
--- /dev/null
+++ b/cusf_launcher_crypto/src/lib.rs
@@ -0,0 +1,35 @@
+use bitcoin_hashes::{hmac, ripemd160, sha512, Hash as _, HashEngine};
+use godot::{builtin::PackedByteArray, prelude::{gdextension, godot_api, ExtensionLibrary, GodotClass}};
+
+struct MyExtension;
+
+#[gdextension]
+unsafe impl ExtensionLibrary for MyExtension {}
+
+#[derive(GodotClass)]
+#[class(no_init)]
+struct Ripemd160;
+
+#[godot_api]
+impl Ripemd160 {
+    #[func]
+    fn digest(msg: PackedByteArray) -> PackedByteArray {
+        let digest = ripemd160::Hash::hash(msg.as_slice());
+        digest.to_byte_array().into()
+    }
+}
+
+#[derive(GodotClass)]
+#[class(no_init)]
+struct HmacSha512;
+
+#[godot_api]
+impl HmacSha512 {
+    #[func]
+    fn hmac(key: PackedByteArray, msg: PackedByteArray) -> PackedByteArray {
+        let mut engine = hmac::HmacEngine::<sha512::Hash>::new(key.as_slice());
+        engine.input(msg.as_slice());
+        let hmac = hmac::Hmac::<sha512::Hash>::from_engine(engine);
+        hmac.to_byte_array().into()
+    }
+}
\ No newline at end of file