Add Changelog entry for RSA exponent blinding
diff --git a/ChangeLog b/ChangeLog
index fe5ce65..15b5557 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
mbed TLS ChangeLog (Sorted per branch, date)
+= mbed TLS 2.1.x branch released xxxx-xx-xx
+
+Security
+ * Add exponent blinding to RSA private operations as a countermeasure
+ against side-channel attacks like the cache attack described in
+ https://arxiv.org/abs/1702.08719v2.
+ Found and fix proposed by Michael Schwarz, Samuel Weiser, Daniel Gruss,
+ Clémentine Maurice and Stefan Mangard.
+
= mbed TLS 2.1.7 branch released 2017-03-08
Security