diff --git a/login_server/src/cpp/JSONInterface/JsonRequestHandlerFactory.cpp b/login_server/src/cpp/JSONInterface/JsonRequestHandlerFactory.cpp
index 744ac710e..188078b7d 100644
--- a/login_server/src/cpp/JSONInterface/JsonRequestHandlerFactory.cpp
+++ b/login_server/src/cpp/JSONInterface/JsonRequestHandlerFactory.cpp
@@ -13,6 +13,7 @@
 #include "JsonCreateTransaction.h"
 #include "JsonCreateUser.h"
 #include "JsonGetLogin.h"
+#include "JsonSignTransaction.h"
 #include "JsonUnknown.h"
 #include "JsonGetRunningUserTasks.h"
 #include "JsonGetUsers.h"
@@ -76,6 +77,9 @@ Poco::Net::HTTPRequestHandler* JsonRequestHandlerFactory::createRequestHandler(c
 	else if (url_first_part == "/checkSessionState") {
 		return new JsonCheckSessionState;
 	}
+	else if (url_first_part == "/signTransaction") {
+		return new JsonSignTransaction;
+	}
 	else if (url_first_part == "/checkUsername") {
 		return new JsonCheckUsername;
 	}
diff --git a/login_server/src/cpp/JSONInterface/JsonSignTransaction.cpp b/login_server/src/cpp/JSONInterface/JsonSignTransaction.cpp
new file mode 100644
index 000000000..f38c4b48f
--- /dev/null
+++ b/login_server/src/cpp/JSONInterface/JsonSignTransaction.cpp
@@ -0,0 +1,48 @@
+#include "JsonSignTransaction.h"
+#include "lib/DataTypeConverter.h"
+
+Poco::JSON::Object* JsonSignTransaction::handle(Poco::Dynamic::Var params)
+{
+	auto result = checkAndLoadSession(params);
+	if (result) {
+		return result;
+	}
+
+	std::string bodyBytes_base64;
+	auto mm = MemoryManager::getInstance();
+
+	// if is json object
+	if (params.type() == typeid(Poco::JSON::Object::Ptr)) {
+		Poco::JSON::Object::Ptr paramJsonObject = params.extract<Poco::JSON::Object::Ptr>();
+		/// Throws a RangeException if the value does not fit
+		/// into the result variable.
+		/// Throws a NotImplementedException if conversion is
+		/// not available for the given type.
+		/// Throws InvalidAccessException if Var is empty.
+		try {
+			paramJsonObject->get("bodyBytes").convert(bodyBytes_base64);
+		}
+		catch (Poco::Exception& ex) {
+			return stateError("json exception", ex.displayText());
+		}
+	}
+	auto user = mSession->getNewUser();
+	auto keyPair = user->getGradidoKeyPair();
+	if (!keyPair) {
+		return stateError("error reading keys");
+	}
+
+	auto bodyBytes = DataTypeConverter::base64ToBin(bodyBytes_base64);
+	auto sign = keyPair->sign(bodyBytes_base64);
+	mm->releaseMemory(bodyBytes);
+	
+	if (!sign) {
+		return stateError("error signing transaction");
+	}
+	auto sign_base64 = DataTypeConverter::binToBase64(sign);
+	mm->releaseMemory(sign);
+	result = stateSuccess();
+	result->set("sign", sign_base64);
+
+	return result;
+}
\ No newline at end of file
diff --git a/login_server/src/cpp/JSONInterface/JsonSignTransaction.h b/login_server/src/cpp/JSONInterface/JsonSignTransaction.h
new file mode 100644
index 000000000..108ae9f3a
--- /dev/null
+++ b/login_server/src/cpp/JSONInterface/JsonSignTransaction.h
@@ -0,0 +1,15 @@
+#ifndef __JSON_INTERFACE_JSON_SIGN_TRANSACTION_
+#define __JSON_INTERFACE_JSON_SIGN_TRANSACTION_
+
+#include "JsonRequestHandler.h"
+
+class JsonSignTransaction : public JsonRequestHandler
+{
+public:
+	Poco::JSON::Object* handle(Poco::Dynamic::Var params);
+
+protected:
+
+};
+
+#endif // __JSON_INTERFACE_JSON_SIGN_TRANSACTION_
\ No newline at end of file