diff --git a/src/common.hpp b/src/common.hpp
index b37f50c..b8523e9 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -90,7 +90,7 @@
 enum {
   EncryptedContent = 130,
   EncryptedPayload = 132,
-  InitialVector = 133,
+  InitializationVector = 133,
   EncryptedPayloadKey = 134,
 };
 
@@ -105,6 +105,10 @@
 const size_t AES_KEY_SIZE = 32;
 const size_t AES_IV_SIZE = 16;
 
+const time::seconds DEFAULT_KEK_FRESHNESS_PERIOD = 1_h;
+const time::seconds DEFAULT_KDK_FRESHNESS_PERIOD = 1_h;
+const time::seconds DEFAULT_CK_FRESHNESS_PERIOD = 1_h;
+
 enum class ErrorCode {
   KekRetrievalFailure = 1,
   KekRetrievalTimeout = 2,
@@ -120,7 +124,8 @@
   CkInvalidName = 23,
 
   MissingRequiredKeyLocator = 101,
-  TpmKeyNotFound = 102
+  TpmKeyNotFound = 102,
+  EncryptionFailure = 103
 };
 
 using ErrorCallback = std::function<void (const ErrorCode&, const std::string&)>;