diff --git a/src/yang/etsi-nfv-common.yang b/src/yang/etsi-nfv-common.yang
index 09ff7ee9045cc9ce4c13fb58c17a32f503afe982..85d778947c7320dd9d2942a652715ceddc195455 100644
--- a/src/yang/etsi-nfv-common.yang
+++ b/src/yang/etsi-nfv-common.yang
@@ -177,6 +177,42 @@ submodule etsi-nfv-common {
     base cp-role;
   }
 
+  identity checksum-algorithm {
+    description
+      "Identifies the algorithms supported for the purpose of
+       calculating the checksum.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
+  }
+
+  identity sha-224 {
+    base checksum-algorithm;
+    description
+      "SHA-224.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
+  }
+
+  identity sha-256 {
+    base checksum-algorithm;
+    description
+      "SHA-256.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
+  }
+
+  identity sha-384 {
+    base checksum-algorithm;
+    description
+      "SHA-384.";
+  }
+
+  identity sha-512 {
+    base checksum-algorithm;
+    description
+      "SHA-512.";
+  }
+      
   /*
    * Typedefs
    */
diff --git a/src/yang/etsi-nfv-vnf.yang b/src/yang/etsi-nfv-vnf.yang
index 2c595850ec15f53377596e2918ba9ba0a5c5a947..4bffa9c8a48b1f8683b3a97c8e9b652725923b62 100755
--- a/src/yang/etsi-nfv-vnf.yang
+++ b/src/yang/etsi-nfv-vnf.yang
@@ -829,7 +829,9 @@ submodule etsi-nfv-vnf {
         }
         container checksum {
           leaf algorithm {
-            type string;
+            type identityref {
+	      base checksum-algorithm;
+	    }
             description
               "Species the algorithm used to obtain the checksum
                value.";