diff --git a/willow/proto/willow/session_enums.proto b/willow/proto/willow/session_enums.proto
index 6aa172a..a356468 100644
--- a/willow/proto/willow/session_enums.proto
+++ b/willow/proto/willow/session_enums.proto
@@ -41,3 +41,10 @@ enum KeyStatus {
   KEY_STATUS_FAILED = 3;
 }
 
+enum DecryptionStatus {
+  DECRYPTION_STATUS_UNSPECIFIED = 0;
+  DECRYPTION_STATUS_PENDING = 1;
+  DECRYPTION_STATUS_COMPLETED = 2;
+  DECRYPTION_STATUS_FAILED = 3;
+}
+