diff --git a/ch04_keys.adoc b/ch04_keys.adoc
index 59036f8e..ffcb9e1b 100644
--- a/ch04_keys.adoc
+++ b/ch04_keys.adoc
@@ -286,7 +286,7 @@ that k is sometimes confusingly called an "exponent" in ((("public key cryptogra
 [[public_key_derivation]]
 ==== Public Keys
 
-The public key is calculated from
+The ((("public key cryptography", "public keys", "generating", id="pub-key-public-generate")))((("public keys", "generating", id="public-key-generate")))public key is calculated from
 the private key using elliptic curve multiplication, which is
 irreversible: _K_ = _k_ * _G_, where _k_ is the private key, _G_ is a
 constant point called the _generator point_, and _K_ is the resulting
@@ -373,7 +373,7 @@ geometric operation on the curve.
 ====
 Many Bitcoin implementations use
 the https://oreil.ly/wD60m[libsecp256k1 crytographic
-library] to do the elliptic curve math.
+library] to do the elliptic curve((("public key cryptography", "public keys", "generating", startref="pub-key-public-generate")))((("public keys", "generating", startref="public-key-generate"))) math.
 ====
 
 [[ecc_illustrated]]