Sigil APK

<p>Sigil is an open-source, advanced encryption utility built for defense-in-depth and memory safety. Unlike standard tools that rely on a single algorithm, Sigil employs a multi-layered, configurable architecture to ensure your data remains secure against sophisticated cryptanalysis.</p><p>The application operates entirely offline, performing all cryptographic operations locally on your device with a modern Material 3 interface that balances high-level security with usability.</p><p><strong>Core Security Features</strong></p><ul><li><strong>Encryption Profiles:</strong> Customize your security posture. Switch between "Standard AES-GCM" (Raw mode) for compatibility with external tools, or the "Sigil Chain" for maximum defense.</li><li><strong>Multi-Layer Cascade:</strong> The default Sigil Chain wraps your data in a hybrid cascade of XChaCha20-Poly1305 + Serpent-CBC + Twofish-CBC + AES-256-GCM. This defense-in-depth approach ensures that even if one algorithm is compromised, your data remains protected by independent layers.</li><li><strong>Zero-Knowledge Auth:</strong> Secure the app with a numeric PIN or a strong alphanumeric Password. Credentials are hashed using Salted Argon2id and never stored in a reversible format.</li><li><strong>Hardware-Backed Vault:</strong> When supported by the device, master keys are generated and stored in the Android Keystore (or StrongBox). Saved encryption passwords never touch the disk in plaintext.</li><li><strong>Memory Hygiene:</strong> Sensitive data buffers are zeroed where possible after use to reduce exposure to memory dumps.</li></ul><p><strong>Privacy &amp; System Hardening</strong></p><ul><li><strong>Screen Security:</strong> Prevents screenshots and hides app content in the "Recent Apps" overview using <code>FLAG_SECURE</code>, protecting against visual snooping and malicious screen recorders.</li><li><strong>Clipboard Protection:</strong> Automatic wipe timers and Android 13+ sensitive content flags prevent clipboard managers from retaining your decrypted data.</li><li><strong>Offline-Only:</strong> Sigil does not request the INTERNET permission. It tracks no analytics, collects no telemetry, and stores no data on external servers.</li></ul><p><strong>Advanced User Toolkit</strong></p><ul><li><strong>Secure Keystore:</strong> Save, view, and manage encryption keys using the hardware-backed vault.</li><li><strong>Custom Encryption Control:</strong> Full manual control over encryption chains. Build your own cascade from 18 algorithms, reorder layers, and toggle ZLib compression.</li><li><strong>System Console:</strong> Real-time logging of the encryption process, providing precise timing metrics and error diagnostics.</li><li><strong>Advanced Theming:</strong> Material You Dynamic Colors, Dark/Light modes, and a custom HSV color engine.</li></ul><p><strong>Technical Specifications</strong></p><ul><li><strong>Key Derivation:</strong> Argon2id (Configurable up to 256MB RAM) + SHA-512 pre-hashing.</li><li><strong>Supported Algorithms:</strong> AES-256-GCM, AES-256-CBC, ChaCha20-Poly1305, XChaCha20-Poly1305, ARIA-256-GCM, Twofish, Serpent, Camellia, CAST6, RC6, SM4, GOST, SEED, Blowfish, IDEA, CAST5, TEA, and XTEA.</li></ul><p><strong>Open-Source Transparency</strong></p><p>The complete source code is available for public audit on GitHub: https://github.com/Animesh-Varma/Sigil</p><p>For the complete release roadmap and planned features, please visit: https://github.com/Animesh-Varma/Sigil/releases</p><p>For any queries, please contact: sigil@animeshvarma.dev</p>