Auditable W3C WebCrypto & Standalone Air-Gapped (.html) Recovery Specification
A digital inheritance or corporate continuity vault must survive longer than any startup, cloud provider, or JavaScript framework. ZeroCanary is engineered on zero-dependency W3C WebCrypto primitives and exports a self-contained HTML5 decryptor capable of offline execution decades from now.
1. Zero-Trust Design Invariants
Security teams evaluating ZeroCanary do not need to trust operator assurances. Every cryptographic operation executes client-side inside standard unminified browser APIs (window.crypto.subtle) governed by strict Content Security Policy headers (default-src 'self'; object-src 'none'; frame-ancestors 'none') with zero third-party scripts, zero analytics trackers, and self-hosted fonts.
| Cryptographic Primitive | Algorithm & Parameters | Security Role in Envelope v3 |
|---|---|---|
| Password Key Stretching | PBKDF2-HMAC-SHA256 (600,000 iterations + 128-bit CSPRNG salt) |
OWASP-compliant high-work-factor resistance against offline GPU brute-force attacks. |
| Key Domain Separation | HKDF-SHA256 with explicit role context labels |
Strictly isolates encryption keys (AES-GCM) from authentication verifiers so server auth material can never derive decryption keys. |
| Payload Confidentiality & AEAD | AES-256-GCM (96-bit fresh CSPRNG IV, 128-bit auth tag) |
Authenticated encryption of text instructions, Cover Notes, and detached binary attachments up to 50 MB. |
| Zero-Knowledge Authentication | RFC 5802 SCRAM-SHA256 mutual challenge-response |
Verifies Owner Main Password or Emergency Duress Password for check-ins and two-way edits without transmitting passwords or reusable hashes. |
| Autonomous Release Notary | Mainnet Threshold secp256k1 ECDSA + SHA-256 commitment |
Anchors deposit payload digest and signs deterministic release authorizations upon timer expiration. |
2. Detached Binary Ciphertext & Multi-File Auto-ZIP Architecture
To support real-world estate and corporate archives—scanned notarized deeds, hardware wallet descriptor bundles, SSH/PGP keys, and financial spreadsheets—without exhausting browser DOM memory:
- Client-Side Multi-File Bundling: Selecting multiple files automatically packages them into a standards-compliant
.ziparchive inside browser RAM before a single byte is encrypted. - Executable Firewall: High-risk executable and script extensions (
.exe,.dll,.bat,.ps1,.sh,.js,.svg) are blocked both client-side and at the edge firewall (HTTP 415). - Sovereign EU Object Custody: Encrypted envelopes and detached binary ciphertext streams (up to
50 MB) are stored exclusively inside European Union jurisdiction zero-knowledge object storage.
3. How the Standalone Offline Recovery Kit (.html) Guarantees 20-Year Survival
Every sealed deposit lets the owner download a single self-contained HTML file containing:
- Embedded Ciphertext (≤20 MB Direct Air-Gap): Text directives and encrypted attachments up to
20 MBare base64-sealed directly inside the HTML document. Opening the file viafile:///on any offline Windows, macOS, or Linux machine with network interfaces disabled decrypts the entire archive locally using native browser WebCrypto. (Larger20–50 MBbinary archives stream ciphertext from EU zero-knowledge custody upon release authorization and decrypt locally in RAM.) - Zero External Dependencies: Built-in multilingual UI (
EN,DE,ES,FR,PL), inline styles, and pure W3C standard WebCrypto calls ensure the file continues working as long as any standards-compliant HTML5 browser exists. - Cryptographic Integrity Verification: Recomputes and verifies the
SHA-256commitment andAES-256-GCMauthentication tag locally prior to rendering or downloading recovered files, rejecting any bit-rot or tampering.
Frequently Asked Architectural Questions
How can an independent security auditor verify that ZeroCanary never transmits plaintext?
Open your browser's Developer Tools (Network tab) on https://zerocanary.com/#enclave, seal a test deposit in the $0 1-Hour Evaluation Sandbox, and inspect every outbound JSON and binary request. Only random salts, SCRAM-SHA256 verifiers, SHA-256 digests, and AES-256-GCM ciphertext leave the browser.
Why use 600,000 iterations of PBKDF2-HMAC-SHA256?
600,000 iterations meets current OWASP Password Storage recommendations for PBKDF2-HMAC-SHA256 while being natively hardware-accelerated across 100% of W3C WebCrypto implementations (Safari, Chrome, Firefox, Edge, and offline file:/// contexts) without requiring external WebAssembly bundles.
Test this continuity architecture in 60 seconds
Seal a live test deposit, verify three-role password separation (Owner, Duress Cover Note, and Recipient), and generate a standalone air-gapped Offline Recovery Kit (.html) in the $0 1-Hour Evaluation Sandbox—or activate a 3M ($49), 6M ($89), 12M ($149), or Law Firm B2B ($490) Continuity Pass.