chore(approaches|use-case): update private auth with more relevant details

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to the IPTF Map are documented here.
 
 ## [Unreleased]
 
+### Changed
+- feat(use-case): Broadened [Private Authentication](use-cases/private-auth.md) beyond institutional KYC to cover governance and national identity use cases
+- feat(approach): Restructured [Private Authentication Approach](approaches/approach-private-auth.md) with credential-source taxonomy and validated deployment references
+
 ### Added
 - feat(pattern): [EY: Starlight](vendors/ey.md#starlight) - Solidity transpiler for private on-chain state. Consolidated EY products into a single vendor file.
 - feat(pattern): [Network-Level Anonymity](patterns/pattern-network-anonymity.md) - Umbrella pattern for transport-layer sender anonymity (Tor, mixnets, private RPC, TEE-assisted, VPN)

GLOSSARY.md

@@ -107,6 +107,12 @@ A dedicated network or service that publishes and stores the data required for D
 
 ### Identity & Compliance
 
+**PCD (Proof-Carrying Data)**: Data bundled with a cryptographic proof of its own correctness, enabling portable and composable verifiable credentials. 
+
+**Sybil Resistance**: Preventing a single actor from creating multiple fake identities to gain disproportionate influence in systems that distribute value, votes, or access.
+
+**DKIM (DomainKeys Identified Mail)**: Email authentication standard where mail servers sign outgoing messages.
+
 **ONCHAINID**: Decentralized identity system used by ERC-3643 for KYC/eligibility verification
 
 **KYC/AML**: Know Your Customer/Anti-Money Laundering regulatory compliance requirements