diff --git a/services/tunnelbroker/src/cxx_bridge.rs b/services/tunnelbroker/src/cxx_bridge.rs
--- a/services/tunnelbroker/src/cxx_bridge.rs
+++ b/services/tunnelbroker/src/cxx_bridge.rs
@@ -1,7 +1,18 @@
 #[cxx::bridge]
 pub mod ffi {
+  struct grpcResult {
+    statusCode: u8,
+    errorText: String,
+  }
+
+  struct SessionSignatureResult {
+    toSign: String,
+    grpcStatus: grpcResult,
+  }
+
   unsafe extern "C++" {
     include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
     pub fn initialization();
+    pub fn sessionSignatureHandler(deviceID: &str) -> SessionSignatureResult;
   }
 }
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.h b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.h
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
@@ -1,5 +1,7 @@
 #pragma once
 
 #include "rust/cxx.h"
+#include "tunnelbroker/src/cxx_bridge.rs.h"
 
 void initialization();
+SessionSignatureResult sessionSignatureHandler(rust::Str deviceID);
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
@@ -7,6 +7,7 @@
 #include "Tools.h"
 
 #include "rust/cxx.h"
+#include "tunnelbroker/src/cxx_bridge.rs.h"
 
 void initialization() {
   comm::network::tools::InitLogging("tunnelbroker");
@@ -35,3 +36,23 @@
   };
   comm::network::AmqpManager::getInstance().init();
 }
+
+SessionSignatureResult sessionSignatureHandler(rust::Str deviceID) {
+  const std::string requestedDeviceID(deviceID);
+  if (!comm::network::tools::validateDeviceID(requestedDeviceID)) {
+    return SessionSignatureResult{
+        .grpcStatus = {
+            .statusCode = 3,
+            .errorText =
+                "Format validation failed for deviceID: " + requestedDeviceID}};
+  }
+  const std::string toSign = comm::network::tools::generateRandomString(
+      comm::network::SIGNATURE_REQUEST_LENGTH);
+  std::shared_ptr<comm::network::database::SessionSignItem> SessionSignItem =
+      std::make_shared<comm::network::database::SessionSignItem>(
+          toSign, requestedDeviceID);
+  comm::network::database::DatabaseManager::getInstance().putSessionSignItem(
+      *SessionSignItem);
+
+  return SessionSignatureResult{.toSign = toSign};
+}
diff --git a/services/tunnelbroker/src/server/mod.rs b/services/tunnelbroker/src/server/mod.rs
--- a/services/tunnelbroker/src/server/mod.rs
+++ b/services/tunnelbroker/src/server/mod.rs
@@ -1,3 +1,4 @@
+use super::cxx_bridge;
 use futures::Stream;
 use std::pin::Pin;
 use tonic::transport::Server;
@@ -5,7 +6,7 @@
 use tunnelbroker::tunnelbroker_service_server::{
   TunnelbrokerService, TunnelbrokerServiceServer,
 };
-
+mod tools;
 mod tunnelbroker {
   tonic::include_proto!("tunnelbroker");
 }
@@ -17,9 +18,19 @@
 impl TunnelbrokerService for TunnelbrokerServiceHandlers {
   async fn session_signature(
     &self,
-    _request: Request<tunnelbroker::SessionSignatureRequest>,
+    request: Request<tunnelbroker::SessionSignatureRequest>,
   ) -> Result<Response<tunnelbroker::SessionSignatureResponse>, Status> {
-    Err(Status::unimplemented("Not implemented yet"))
+    let result =
+      cxx_bridge::ffi::sessionSignatureHandler(&request.into_inner().device_id);
+    if result.grpcStatus.statusCode > 0 {
+      return Err(tools::create_tonic_status(
+        result.grpcStatus.statusCode,
+        &result.grpcStatus.errorText,
+      ));
+    }
+    Ok(Response::new(tunnelbroker::SessionSignatureResponse {
+      to_sign: result.toSign,
+    }))
   }
 
   async fn new_session(
diff --git a/services/tunnelbroker/src/server/tools.rs b/services/tunnelbroker/src/server/tools.rs
new file mode 100644
--- /dev/null
+++ b/services/tunnelbroker/src/server/tools.rs
@@ -0,0 +1,25 @@
+use tonic::{Code, Status};
+
+pub fn create_tonic_status(code: u8, text: &str) -> Status {
+  let status = match code {
+    0 => Code::Ok,
+    1 => Code::Cancelled,
+    2 => Code::Unknown,
+    3 => Code::InvalidArgument,
+    4 => Code::DeadlineExceeded,
+    5 => Code::NotFound,
+    6 => Code::AlreadyExists,
+    7 => Code::PermissionDenied,
+    8 => Code::ResourceExhausted,
+    9 => Code::FailedPrecondition,
+    10 => Code::Aborted,
+    11 => Code::OutOfRange,
+    12 => Code::Unimplemented,
+    13 => Code::Internal,
+    14 => Code::Unavailable,
+    15 => Code::DataLoss,
+    16 => Code::Unauthenticated,
+    _ => Code::Internal,
+  };
+  Status::new(status, text)
+}