Security Architecture
Every statement below has been checked directly against the SANITHIUM Wallet codebase. Where protections are in development or externally unaudited, we state those limits plainly.
Audit & Custody Disclaimer: Independent third-party security auditing has not been completed, and no formal certification or insurance applies. SANITHIUM cannot guarantee immunity against device compromise or user error, and cannot recover lost recovery phrases, reset wallets, or reverse broadcast transactions. Users are solely responsible for safeguarding their recovery phrases and private keys.
Code-Reviewed Controls
Reviewed against CryptoProvider & SecurityWarningScreen.
12-word or 24-word BIP-39 recovery phrases are generated strictly on the user's device using platform cryptographically secure random sources. SANITHIUM stores zero keys on any server and cannot reset, recover, or restore a lost phrase.
Reviewed against WalletVault & PinService.
The recovery phrase is encrypted with AES-256-GCM (128-bit authentication tag, 12-byte random IV) using an ephemeral 256-bit K_MASTER, which is itself wrapped by K_PIN derived from a 6-digit PIN via PBKDF2-HMAC-SHA256 (100,000 iterations, separate 32-byte auth and encryption salts).
Reviewed against PinService.
PIN verification compares derived tokens in constant time to resist timing side-channels. Four failed attempts enforce a 30-second delay, attempts 5–9 apply quadratic minute lockouts (1, 4, 9, 16, and 25 minutes), and 10 consecutive failures enforce a 24-hour soft lockout requiring recovery phrase re-import.
Reviewed against SecureTransactionSigner & TransactionIntegrityBinding.
Every transaction requires explicit PIN confirmation producing a 60-second single-use SigningAuthorizationScope. TransactionIntegrityBinding ensures the exact network, recipient, value, and fee shown on the review screen match the payload signed offline.
Reviewed against MainActivity.kt & AndroidManifest.xml.
Android builds apply WindowManager.LayoutParams.FLAG_SECURE to prevent screenshots, screen recordings, and app-switcher thumbnail previews, and configure android:allowBackup="false" to block cloud backup extraction of local storage.
Reviewed against MainActivity.kt & lib/ source files.
No independent third-party security audit, formal certification, or insurance coverage has been completed. Runtime root/jailbreak detection (flutter_jailbreak_detection) is present as a dependency but not yet wired into active startup blocking, and biometric unlock currently relies on local_auth plus EncryptedSharedPreferences AES-GCM storage rather than custom native Kotlin KeyStore key binding.
eth_sign and key-export methods are explicitly denylisted in Web3RequestValidator.If you identify a cryptographic, protocol, or web security issue affecting SANITHIUM Wallet or sanithium.io, report reproduction steps responsibly to security@sanithium.io or via our support portal. Please avoid testing against third-party RPC nodes or disclosing issues publicly prior to remediation review.