add xref

diff --git a/src/theory/PKIs.tex b/src/theory/PKIs.tex
index 1efc916..23ae8c8 100644 (file)
--- a/src/theory/PKIs.tex
+++ b/src/theory/PKIs.tex
@@ -12,7 +12,8 @@ Certificate Authorities (CAs) sign end-entities' certificates, thereby
 associating some kind of identity (e.g. a domain name or an email
 address) with a public key. CAs are used with TLS and S/MIME
 certificates, and the CA system has a big list of possible and real
-problems which are summarized in \cite{https13}.
+problems which are summarized in section \ref{sec:hardeningpki} and
+\cite{https13}.
 
 The Web of Trust is a decentralized system where people sign each
 others keys, so that there is a high chance that there is a ``trust