diff --git a/ch08_signatures.adoc b/ch08_signatures.adoc
index 71bf369d..48d3082f 100644
--- a/ch08_signatures.adoc
+++ b/ch08_signatures.adoc
@@ -290,7 +290,7 @@ other applications use, although it is perhaps most strongly associated
 with ECC today.  Schnorr signatures have a number of nice properties:
 
 Provable security::
-  A mathematical proof of the security of schnorr signatures depends on
+  A mathematical ((("digital signatures", "schnorr signature algorithm", "properties of")))((("schnorr signature algorithm", "properties of")))proof of the security of schnorr signatures depends on
   only the difficulty of solving the Discrete Logarithm Problem (DLP),
   particularly for elliptic curves (EC) for Bitcoin, and the ability of
   a hash function (like the SHA256 function used in Bitcoin) to produce