diff --git a/src/yang/etsi-nfv-common.yang b/src/yang/etsi-nfv-common.yang
index 23092426674b924167c950a593d8e903b548d710..2f6a69a9329b3a886411cb0e17c6bf6d1763cf20 100644
--- a/src/yang/etsi-nfv-common.yang
+++ b/src/yang/etsi-nfv-common.yang
@@ -177,6 +177,46 @@ 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.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
+  }
+
+  identity sha-512 {
+    base checksum-algorithm;
+    description
+      "SHA-512.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
+  }
+      
   /*
    * Typedefs
    */
diff --git a/src/yang/etsi-nfv-vnf.yang b/src/yang/etsi-nfv-vnf.yang
index 112fe39331226468666ad931b5e489ee36f659f2..28e81604b242e555174edc0c35932dbccc565928 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.";