diff --git a/protobuf/asym_sign.proto b/protobuf/asym_sign.proto
index 98e7993..c088176 100644
--- a/protobuf/asym_sign.proto
+++ b/protobuf/asym_sign.proto
@@ -16,16 +16,14 @@
  */
 syntax = "proto3";
 
-import "key_attributes.proto";
-
 package asym_sign;
 
 message OpAsymmetricSignProto {
     string key_name = 1;
-    key_attributes.KeyLifetime key_lifetime = 2;
+    reserved 2;
     bytes hash = 3;
 }
 
 message ResultAsymmetricSignProto {
     bytes signature = 1;
-}
\ No newline at end of file
+}
diff --git a/protobuf/asym_verify.proto b/protobuf/asym_verify.proto
index 5c95723..06fdd24 100644
--- a/protobuf/asym_verify.proto
+++ b/protobuf/asym_verify.proto
@@ -16,15 +16,13 @@
  */
 syntax = "proto3";
 
-import "key_attributes.proto";
-
 package asym_verify;
 
 message OpAsymmetricVerifyProto {
     string key_name = 1;
-    key_attributes.KeyLifetime key_lifetime = 2;
+    reserved 2;
     bytes hash = 3;
     bytes signature = 4;
 }
 
-message ResultAsymmetricVerifyProto { }
\ No newline at end of file
+message ResultAsymmetricVerifyProto { }
diff --git a/protobuf/destroy_key.proto b/protobuf/destroy_key.proto
index fbb5cd1..d8c91d7 100644
--- a/protobuf/destroy_key.proto
+++ b/protobuf/destroy_key.proto
@@ -16,13 +16,11 @@
  */
 syntax = "proto3";
 
-import "key_attributes.proto";
-
 package destroy_key;
 
 message OpDestroyKeyProto {
     string key_name = 1;
-    key_attributes.KeyLifetime key_lifetime = 2;
+    reserved 2;
 }
 
-message ResultDestroyKeyProto { }
\ No newline at end of file
+message ResultDestroyKeyProto { }
diff --git a/protobuf/export_public_key.proto b/protobuf/export_public_key.proto
index 6d598b7..8adfdda 100644
--- a/protobuf/export_public_key.proto
+++ b/protobuf/export_public_key.proto
@@ -16,15 +16,13 @@
  */
 syntax = "proto3";
 
-import "key_attributes.proto";
-
 package export_public_key;
 
 message OpExportPublicKeyProto {
    string key_name = 1;
-   key_attributes.KeyLifetime key_lifetime = 2;
+   reserved 2;
 }
 
 message ResultExportPublicKeyProto {
    bytes key_data = 1;
-}
\ No newline at end of file
+}
diff --git a/protobuf/key_attributes.proto b/protobuf/key_attributes.proto
index 801638c..2da7e31 100644
--- a/protobuf/key_attributes.proto
+++ b/protobuf/key_attributes.proto
@@ -18,11 +18,6 @@ syntax = "proto3";
 
 package key_attributes;
 
-enum KeyLifetime {
-   Volatile = 0;
-   Persistent = 1;
-}
-
 enum KeyType {
    HMAC_Key = 0;
    Derivation_Key = 1;
@@ -171,7 +166,7 @@ message KeyAgreement {
 }
 
 message KeyAttributesProto {
-   KeyLifetime key_lifetime = 1;
+   reserved 1;
    KeyType key_type = 2;
    EccCurve ecc_curve = 3;
    oneof algorithm_proto {
@@ -191,4 +186,4 @@ message KeyAttributesProto {
    bool permit_sign = 8;
    bool permit_verify = 9;
    bool permit_derive = 10;
-}
\ No newline at end of file
+}