Blitz preserves an offline exit bundle but exports the actual recovery outside the wallet

What the evidence shows

Technical and product details

1. Material mitigation

   Blitz stores raw Spark leaves and ancestor nodes in SQLite, refreshes them while Operators are reachable, and can build a spark.unilateral-exit-bundle.v1 file that remains usable as input while the Operators are offline. 12

   Supporting material shown on this page

   Blitz exit-state storagePinned source code · github.com · checked 2026-08-24

   152// ---------------------------------------------------------------------------
   153// Normalization: raw SDK TreeNode -> JSON-serializable, all bytes hex-encoded.
   154// Every field returned by getLeaves() is public (public keys, FROST public
   155// shares, and Bitcoin transactions that pay back to the owner), so nothing here
   156// is encrypted. We keep the FULL leaf (including the directTx variants the
   157// SDK's WalletLeaf DTO drops) so the export is a complete unilateral-exit copy.
   158// ---------------------------------------------------------------------------

   Blitz bundle exportPinned source code · github.com · checked 2026-08-24

   150            'unilateral exit of multi-level trees needs live Spark operators or ' +
   151            'the reference Rust exporter (tools/spark-recovery-bundle). See the ' +
   152            'spark-unilateral-exit guide.';
   153
   154        const fileData =
   155          `{"schema":"spark.unilateral-exit-bundle.v1",` +
   156          `"createdAt":${JSON.stringify(new Date().toISOString())},` +

2. Missing product stages

   The app does not fund, construct, package-relay, monitor, resume, refund, or sweep the exit. Its export notes direct the user to the separate Spark unilateral-exit guide. 3

   Supporting material shown on this page

   Blitz external recovery directionPinned source code · github.com · checked 2026-08-24

   143        const networkLabel = NETWORK_LABELS[networkInt] || 'MAINNET';
   144        const recoveryNotes = hasAncestors
   145          ? 'Includes each leaf plus its ancestor TreeNodes up to the tree root, ' +
   146            'captured from Spark operators at export time, so this bundle can ' +
   147            'drive an offline unilateral exit of multi-level trees. Refresh it ' +
   148            'after any wallet activity. See the spark-unilateral-exit guide.'
   149          : 'Leaves only. Ancestor/parent TreeNodes are not included; offline ' +

3. Assessment

   Blitz is the closest reviewed wallet to preserving the prerequisite state, but backup export is not unilateral-exit execution. The ordinary mobile user still has no in-app path from outage to recovered coins. 23

   Supporting material shown on this page

   Blitz bundle exportPinned source code · github.com · checked 2026-08-24

   150            'unilateral exit of multi-level trees needs live Spark operators or ' +
   151            'the reference Rust exporter (tools/spark-recovery-bundle). See the ' +
   152            'spark-unilateral-exit guide.';
   153
   154        const fileData =
   155          `{"schema":"spark.unilateral-exit-bundle.v1",` +
   156          `"createdAt":${JSON.stringify(new Date().toISOString())},` +

   Blitz external recovery directionPinned source code · github.com · checked 2026-08-24

   143        const networkLabel = NETWORK_LABELS[networkInt] || 'MAINNET';
   144        const recoveryNotes = hasAncestors
   145          ? 'Includes each leaf plus its ancestor TreeNodes up to the tree root, ' +
   146            'captured from Spark operators at export time, so this bundle can ' +
   147            'drive an offline unilateral exit of multi-level trees. Refresh it ' +
   148            'after any wallet activity. See the spark-unilateral-exit guide.'
   149          : 'Leaves only. Ancestor/parent TreeNodes are not included; offline ' +

Scope control

What this does not establish

• This finding credits Blitz's real recovery-state work. It does not describe the bundle as useless or claim an expert cannot complete the exit with separate tooling. 12

Sources and excerpts

Primary sources

The relevant details and available source-code excerpts appear alongside the claims above. This list preserves the complete original-source trail for independent verification.