What makes a computational entity itself? When a synthetic organism undergoes a personality transition, when an AI agent is replicated across servers, when a governed process is checkpointed and restored from backup — is the result the same entity or a different one? The DAIGS ecosystem governs matter (Quantum), time (Chronos), space (Dimensional), and causality (Causal), but none of these substrates answers the identity question: what persists when everything else changes? I introduce Lume‑Identity, a deterministic substrate for identity governance. Lume‑Identity defines identity as a governed primitive — not a database record, not a UUID, not a cryptographic key, but a certified, invariant‑enforced, policy‑governed object that persists across temporal transitions (time), dimensional transitions (space), state transitions (mutation), and causal transitions (cause/effect). Every identity state change is indexed by an IdIndex, recorded in the Identity Chain (I‑Chain), and certified by the Identity Certificate Authority. I formalize the Identity model, define eight identity invariants, specify four certificate types, present the Identity Reconstruction Engine (which can rebuild any entity's identity at any past moment), and demonstrate how identity composes with the four other physics substrates to provide the most complete governance of selfhood ever specified for computational systems. Lume‑Identity is the substrate that makes synthetic organisms organisms — persistent, continuous, self‑identical beings rather than stateless processes.
Ronald Jason Andrews (Mon,) studied this question.