Edited ch04_keys.adoc with Atlas code editor

ch04_keys.adoc

@@ -999,7 +999,7 @@ types of addresses to eliminate address collision attacks((("public key cryptogr
 
 === Bech32 Addresses
 
-In 2017, the Bitcoin protocol was upgraded.  When the upgrade is used,
+In 2017, the ((("public key cryptography", "bech32 addresses", "advantages of", id="pub-key-bech32-adv")))((("bech32 addresses", "advantages of", id="bech32-adv")))Bitcoin protocol was upgraded.  When the upgrade is used,
 it prevents transaction
 identifiers (txids) from being changed without the consent of a spending
 user (or a quorum of signers when multiple signatures are required).
@@ -1023,7 +1023,7 @@ getting all wallets to upgrade to new scripts with a new base58check
 version was expected to require almost as much work as getting them to
 upgrade to an entirely new address format, so several Bitcoin
 contributors set out to design the best possible address format.  They
-identified several problems with base58check:
+identified several problems((("public key cryptography", "base58check encoding")))((("base58check encoding")))((("encoding", "base58check"))) with base58check:
 
 - Its mixed-case presentation made it inconvenient to read aloud or
   transcribe.  Try reading one of the legacy addresses in this chapter
@@ -1103,7 +1103,7 @@ image::images/mbc3_0409.png["The same bech32 address QR encoded in lowercase and
   and have that wallet remain able to spend to bech32 addresses for
   users of new features added in future protocol upgrades.  It was
   hoped that we might never again need to go through the system-wide
-  upgrade cycles necessary to allow people to fully use P2SH and segwit.
+  upgrade cycles necessary to allow people to fully use P2SH and((("public key cryptography", "bech32 addresses", "advantages of", startref="pub-key-bech32-adv")))((("bech32 addresses", "advantages of", startref="bech32-adv"))) segwit.
 
 ==== Problems with Bech32 Addresses