diff --git a/common/protocol/headers.proto b/common/protocol/headers.proto
new file mode 100644
index 000000000..a9b71d2da
--- /dev/null
+++ b/common/protocol/headers.proto
@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+package v2ray.core.common.protocol;
+option go_package = "protocol";
+option java_package = "com.v2ray.core.common.protocol";
+option java_outer_classname = "HeadersProto";
+
+enum SecurityType {
+  LEGACY = 0;
+  NONE = 1;
+  AES128_GCM = 2;
+  CHACHA20_POLY1305 = 3;
+}