diff --git a/PARITY.md b/PARITY.md
index 24a54f5..760b629 100644
--- a/PARITY.md
+++ b/PARITY.md
@@ -113,7 +113,7 @@ From `E2E/E2EInbox.swift`, which is the real feature list.
 | Trust state, verification, identity-change acceptance | ✅ pinned in the vault, surfaced on the thread |
 | Key-log enforcement and head gossip | ✅ opt-in enforcement, gossip detects a fork |
 | Clear thread | ✅ keeps the session, so the chat still works |
-| History at rest (encrypted, device-only key) | ⚪ |
+| History at rest (encrypted, device-only key) | ✅ **this row was stale** — sealed per thread under a Keystore key, read straight from disk; see below |
 | Presence (read and set) | ✅ shown from the relay, never inferred |
 | Buddy list, add by username | ✅ |
 | Remove, block, unblock | ✅ |
@@ -121,7 +121,35 @@ From `E2E/E2EInbox.swift`, which is the real feature list.
 | Buddy commands | — retired; not a feature any more (owner, 2026-08-25) |
 | Voice calls (WebRTC, DTLS-SRTP, TURN) | ✅ P2P-first; ⚠️ no TURN deployed |
 | Notifications list, read state | ✅ |
-| Services (AIM/ICQ via `flamenet-oscar`) | ⚪ |
+| Services (AIM/ICQ via `flamenet-oscar`) | — retired; not a goal for this app (owner, 2026-09-04) |
+
+🔴 **History at rest was marked ⚪ and it has been built the whole time — the
+third stale row in this file.** Every read goes to disk: `Session.history` calls
+`Vault.history`, which decrypts the record. There is no in-memory copy to be
+fooled by.
+
+What Android does, against what iOS's `E2EHistoryStore` does:
+
+| | iOS | Android |
+|---|---|---|
+| Cipher | AES-256-GCM | AES-256-GCM |
+| Key | Keychain, `ThisDeviceOnly` | Android Keystore — never leaves the process at all |
+| Bound to its slot | one file, nothing to confuse | 🟢 **the record NAME is the AAD**, so a blob cannot be moved between slots |
+| Shape | one snapshot for everything | one record per thread |
+| Off backups | excluded from iCloud | `allowBackup="false"`, and a Keystore key is unbackupable anyway |
+| At rest, locked | `.completeFileProtection` | Credential-Encrypted storage: `filesDir` is unreadable until the first unlock after boot |
+| Plain sign-out | keeps history | keeps history |
+| Erase this device | `eraseLocalData()` | `forgetEverything()` **and** the Keystore key is deleted |
+
+⚠️ Two honest differences rather than a claim of equivalence. Android's
+per-record AAD is a binding iOS's single file does not need; iOS's
+`.completeFileProtection` is a per-file assertion, while Android's equivalent is
+a property of the storage volume rather than of this app's request. Neither gap
+favours one platform overall.
+
+⚠️ `Vault.history` prunes expired messages on the way out, so disappearing
+messages are enforced on READ rather than by a timer nothing runs. It rewrites
+the record only when something actually expired — a read is not a write.
 
 ✅ Calls are built, on `io.github.webrtc-sdk:android` — the one third-party
 library in this app, and unavoidable: the alternative is hand-rolling ICE,