The macOS Keychain and the Secure Enclave

Every secret on a Mac — a password, a signing key, a Wi-Fi credential, a TLS client certificate — lives behind a cryptographic stack that most developers never see. This book takes it apart.

It begins with the Keychain: how securityd mediates every access, why macOS has two distinct implementations (file-based with ACLs, Data Protection with access groups), and which one modern code should target. ...