Reworded security section about NDEF signature (#518)

* Reworded security section about NDEF signature

* Remove inaccurate statement

* Address feedback

* Remove sentence

Author: beaufortfrancois

index.html

@@ -4080,11 +4080,8 @@ <h3>Parsing content</h3>
 <!-- - - - - - - - - - - - - Security and Privacy - - - - - - - - - - - - - -->
 <section> <h2 id="security">Security and Privacy</h2>
   <p>
-    NFC technology involves multiple levels of security. Payments done with NFC
-    are considered to be secure at hardware level, but the whole software stack
-    needs to be security hardened.
-    However, NFC data transfers involve additional threats. In order to mitigate
-    these, the NFC Forum introduced [[NDEF-SIGNATURE]].
+    In order to protect the integrity and authenticity of NDEF messages, the NFC
+    Forum introduced [[NDEF-SIGNATURE]].
   </p>
 
   <section> <h3>Chain of trust</h3>