diff --git a/ch13_security.adoc b/ch13_security.adoc
index 9f2beb3a..d45e67e9 100644
--- a/ch13_security.adoc
+++ b/ch13_security.adoc
@@ -92,7 +92,7 @@ ultimately subvert Bitcoin's ((("decentralized consensus", "as security principl
 
 ==== The Root of Trust
 
-Traditional security architecture is based
+Traditional ((("root of trust", id="root-trust")))security architecture is based
 upon a concept called the _root of trust_, which is a trusted core used
 as the foundation for the security of the overall system or application.
 Security architecture is developed around the root of trust as a series
@@ -140,7 +140,7 @@ this point because their security architecture and design fails even
 under the most casual scrutiny. These centralized implementations had
 invested trust explicitly in numerous components outside the Bitcoin
 blockchain, such as hot wallets, centralized databases,
-vulnerable encryption keys, and ((("Bitcoin", "security", "principles of", startref="bitcoin-security-principle")))((("security", "principles of", startref="security-principle")))similar schemes.
+vulnerable encryption keys, and ((("Bitcoin", "security", "principles of", startref="bitcoin-security-principle")))((("security", "principles of", startref="security-principle")))((("root of trust", startref="root-trust")))similar schemes.
 
 === User Security Best Practices