signature: Rename KeyLocatorDigest into KeyDigest

Change-Id: Ide8cace988e95269ec057786fc80db8036984c7f
diff --git a/changelog.rst b/changelog.rst
index f402bbe..fac1e35 100644
--- a/changelog.rst
+++ b/changelog.rst
@@ -7,6 +7,7 @@
 - **Signature**
 
   + New ``SignatureSha256WithEcdsa`` signature type for Elliptic Curve Digital Signature Algorithm (ECDSA)
+  + ``KeyLocatorDigest`` renamed to ``KeyDigest``.  The specification now explicitly allows KeyDigest to be a SHA256 of any type of the key.
 
 Since CCNx 0.7.2
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