<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 m