Review of Spark's trust model

Unilateral-exit readiness

No complete in-app unilateral exit was found across eight reviewed consumer-wallet surfaces

The reviewed snapshots and public interfaces for Blink, Primal, Cake, Blitz, Radar, Club Orange, Wallet of Satoshi, and Bringin exposed no complete in-app sequence for preserving current exit state, supplying CPFP funds, ordered broadcasting, durable resume, timelock handling, and final sweeping. Closed-source findings are limited to public claims and observed interfaces. 1234567891011

11 sourcesEvidence reviewed through July 14, 2026

What the evidence shows

Technical and product details

  1. Documented behavior

    At the pinned snapshots and review date, no complete in-app flow covering state acquisition, fee funding, ordered package broadcast, durable progress, timelock waiting, refund broadcast, and final sweep was found for Blink, Primal, Cake, Blitz, Radar, Club Orange, Wallet of Satoshi, or Bringin. 1234567891011

    Supporting material shown on this page

    Blink mobileRepository record · github.com · checked 2026-07-14
    Primal iOSRepository record · github.com · checked 2026-07-14
    CakeRepository record · github.com · checked 2026-07-14
    Radar AndroidRepository record · github.com · checked 2026-07-14
    Radar iOSRepository record · github.com · checked 2026-07-14
    BlitzRepository record · github.com · checked 2026-07-14
    Bringin launchBlog or announcement · bringin.app · checked 2026-07-14
  2. Open-source and binary review

    Blink, Primal, Cake, Radar, and Blitz were reviewed at named commits. Club Orange was reviewed through its published 4.1.8 APK and release record. The audit terms, exclusions, artifact hash, and results are recorded in the consumer-wallet audit manifest. 1234567811

    Supporting material shown on this page

    Blink mobileRepository record · github.com · checked 2026-07-14
    Primal iOSRepository record · github.com · checked 2026-07-14
    CakeRepository record · github.com · checked 2026-07-14
    Radar AndroidRepository record · github.com · checked 2026-07-14
    Radar iOSRepository record · github.com · checked 2026-07-14
    BlitzRepository record · github.com · checked 2026-07-14
  3. Closed-source review

    Wallet of Satoshi and Bringin publish custody or exit claims but not their mobile-app source or a complete consumer unilateral-exit procedure. 910

    Supporting material shown on this page

    Bringin launchBlog or announcement · bringin.app · checked 2026-07-14
  4. Product consequence

    The reviewed record did not demonstrate an ordinary mobile user completing the full operatorless path inside any of the eight wallet interfaces. 1234567891011

    Supporting material shown on this page

    Blink mobileRepository record · github.com · checked 2026-07-14
    Primal iOSRepository record · github.com · checked 2026-07-14
    CakeRepository record · github.com · checked 2026-07-14
    Radar AndroidRepository record · github.com · checked 2026-07-14
    Radar iOSRepository record · github.com · checked 2026-07-14
    BlitzRepository record · github.com · checked 2026-07-14
    Bringin launchBlog or announcement · bringin.app · checked 2026-07-14

Product-level detail

What was found in each reviewed wallet

The conclusions below are reproduced here so the reader does not need to open the separate implementation review. Each result remains limited to the named source snapshot, published binary, or public product surface.

Blink

Surface reviewed: public mobile source

The tracked app backup and restore paths center on the mnemonic; no complete recovery-bundle export and operatorless execution workflow was found. Blink's separate recovery repository labels mobile integration a proposed boundary.

Capabilities that were present: mnemonic backup and restore; ordinary Breez Spark wallet operations.

The separate Blink command-line recovery project is not treated as an in-app mobile workflow.

Primal

Surface reviewed: public android and ios source

No source-visible recovery-bundle handling or complete operatorless package-broadcast, monitoring, refund, and sweep UI flow was found in either pinned application.

Capabilities that were present: seed backup and live-network wallet restore; ordinary Breez Spark wallet operations.

The result is bounded to the two pinned public repositories and does not test an unpublished build.

Cake Wallet

Surface reviewed: public mobile source

No recovery-bundle handling or complete unilateral-exit product flow was found at the pinned snapshot. Breez's public mobile exit API targeted for this dependency generation had not shipped.

Capabilities that were present: mnemonic or seed initialization; Spark, Lightning, and cooperative Bitcoin-address payments.

The public Cake article describes a protocol-level response to an attack; it does not expressly claim that the audited UI contains an exit button.

Blitz Wallet

Surface reviewed: public mobile source

The pre-release adds a meaningful exit-state exporter, but the app does not itself fund CPFP children, construct and broadcast the full sequence, persist confirmation progress, wait through timelocks, broadcast refunds, or sweep final outputs.

Capabilities that were present: best-effort online refresh of eligible leaf ancestry; spark.unilateral-exit-bundle.v1 export through the device share sheet; links to external Blink and Spark recovery documentation.

Bundle export is a real prerequisite and is not characterized as useless.

Radar

Surface reviewed: public android and ios source

Neither pinned app exposed current-exit-state export or the complete CPFP, ordered package, durable monitoring, timelock, refund, and sweep workflow.

Capabilities that were present: seed backup and live-network restoration in a Spark-compatible wallet; ordinary Breez Spark wallet operations.

The result is bounded to the two pinned public repositories.

Club Orange

Surface reviewed: published android apk

No unilateral-exit, exit, or recovery operation appears in the 46 exported BreezSdk method names, and the targeted DEX search found no corresponding user-flow strings. The bundled native library nevertheless contains lower-level unilateral-exit primitives.

Capabilities that were present: the bundled native library contains lower-level unilateral-exit primitives.

Symbol and string searches cannot prove the absence of obfuscated or indirectly invoked private code.

Wallet of Satoshi

Surface reviewed: public documentation and source availability

No published consumer procedure was found for exporting current exit state and executing the complete operatorless workflow. Because the app is closed source, this is a public-verifiability and documented-product finding only.

Capabilities that were present: published description of unilateral exit as a permissionless alternative; seed-backup and ordinary wallet-restore guidance.

No source-code absence claim is made.

Bringin

Surface reviewed: public documentation and source availability

Bringin's public organization did not contain the mobile application, and the reviewed launch and product material supplied no operational procedure for the eight-stage workflow. This does not test private application code.

Capabilities that were present: first-party claim that each wallet ships with pre-signed exits and can leave without Bringin cooperation.

No source-code absence claim is made because Bringin does not publish the reviewed mobile-app source.

See versions, search method, artifact hashes, and full review limits.

Scope control

What this does not establish

  • This is a dated review of named public repositories, one published binary, and public product records. It cannot rule out unavailable code, obfuscated functionality, or later versions. For Wallet of Satoshi and Bringin, the finding is limited to publicly verifiable claims, instructions, and product behavior. 11910

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.

1

Blink mobile

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
2

Primal Android

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
3

Primal iOS

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
4

Cake

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
5

Radar Android

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
6

Radar iOS

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
7

Blitz

Repository record · github.com · Pinned or archival · checked 2026-07-14

Open original source
8

Club Orange releases

Repository record · github.com · Live source · checked 2026-07-14

Open original source
9

Wallet of Satoshi disclosure

Web source · walletofsatoshi.com · Live source · checked 2026-07-14

Open original source
10

Bringin launch

Blog or announcement · bringin.app · Live source · checked 2026-07-14

Open original source
11

consumer-wallet exit audit manifest

Reproducible audit manifest · Review of Spark's trust model · Pinned or archival · checked 2026-07-14

Open original source

How sources, absence findings, and limitations were evaluated