About Sigil
About Sigil
Sigil is an open-source, advanced text encryption utility designed for zero-trust environments. It provides a cryptographic workbench for users who require defense-in-depth security strategies. Unlike standard encryption tools that rely on a single algorithm, Sigil employs a multi-layered, randomized chaining architecture to ensure data remains secure even against sophisticated cryptanalysis.
The application operates entirely offline, performing all cryptographic operations locally on the device. It features a modern, Material 3 interface that balances high-level security with professional usability.
Core Security Features
• Access Control & Volatility: The application is guarded by a strict App Lock (Biometric or PIN) and employs an aggressive memory clearing mechanism that instantly wipes sensitive data from RAM when the app enters the background (configurable in the settings).
• Hardware-Backed Vault: Master keys are generated and stored within the Android Trusted Execution Environment (TEE). Your saved encryption passwords never touch the disk in plaintext.
• Multi-Layer Chaining: In Auto Mode, Sigil randomizes the order of encryption algorithms for every message. A typical chain utilizes AES-256-GCM, Twofish-CBC, and Serpent-CBC in a randomized sequence.
• Tamper-Proof Design: Sigil utilizes an Encrypt-then-MAC architecture. A Global HMAC-SHA256 signature is applied to the final container, ensuring that any tampering or corruption is detected and rejected before decryption is attempted.
• Screen Shield: Sigil prevents visual eavesdropping by blocking screenshots and hiding the application content in the "Recent Apps" overview (using FLAG_SECURE).
Advanced User Toolkit
• Interactive Onboarding: A comprehensive, guided simulation introduces new users to the zero-trust philosophy, demonstrating live encryption cycles and safe key management without risking real data.
• Secure Keystore: Manage your complex keys securely. You can save, name, and recall encryption keys using the hardware-backed vault, eliminating the need to type long passwords repeatedly.
• Custom Cryptographic Workbench: Users have full manual control to design their own encryption chains. You can add, remove, and reorder layers, selecting from a registry of over 15 industrial and legacy standards.
• System Console: A built-in logging interface provides real-time auditing of the encryption process, including timing metrics and detailed error diagnostics.
• Advanced Theming: Full control over the visual environment, including Material You support, forced Dark Mode, and a custom HSV color engine.
Technical Specifications
• Cryptographic Engine: Powered by CryptoEngine v0.9.0 (utilizing Bouncy Castle) for robust algorithm implementation.
• Key Derivation: Keys are derived using Argon2id with high memory hardening (64MB) combined with SHA-512 pre-hashing to resist GPU-based brute-force attacks.
• Key Separation: The application uses HKDF (HMAC-based Key Derivation Function) to generate mathematically distinct keys for every layer and header from the root secret.
• Supported Algorithms: AES (GCM/CBC), Twofish, Serpent, Camellia, CAST6, RC6, SM4, GOST, SEED, Blowfish, IDEA, CAST5, TEA, and XTEA.
Privacy, Permissions & Open Source
Sigil is a zero-knowledge application committed to transparency.
• Open Source: The complete source code is available for public audit at https://github.com/Animesh-Varma/Sigil, ensuring no hidden backdoors or vulnerabilities.
• Offline Only: It does not require internet access, does not track usage analytics, and does not store data on external servers.
• User Controlled Storage: Data exists only during the active session. Passwords are never stored permanently unless you explicitly save them to the Keystore.
Updates & Changelog
To view the latest version catalog and see exactly what has changed in this release, please visit the Release tab located in the application's side menu.
Sigil is an open-source, advanced text encryption utility designed for zero-trust environments. It provides a cryptographic workbench for users who require defense-in-depth security strategies. Unlike standard encryption tools that rely on a single algorithm, Sigil employs a multi-layered, randomized chaining architecture to ensure data remains secure even against sophisticated cryptanalysis.
The application operates entirely offline, performing all cryptographic operations locally on the device. It features a modern, Material 3 interface that balances high-level security with professional usability.
Core Security Features
• Access Control & Volatility: The application is guarded by a strict App Lock (Biometric or PIN) and employs an aggressive memory clearing mechanism that instantly wipes sensitive data from RAM when the app enters the background (configurable in the settings).
• Hardware-Backed Vault: Master keys are generated and stored within the Android Trusted Execution Environment (TEE). Your saved encryption passwords never touch the disk in plaintext.
• Multi-Layer Chaining: In Auto Mode, Sigil randomizes the order of encryption algorithms for every message. A typical chain utilizes AES-256-GCM, Twofish-CBC, and Serpent-CBC in a randomized sequence.
• Tamper-Proof Design: Sigil utilizes an Encrypt-then-MAC architecture. A Global HMAC-SHA256 signature is applied to the final container, ensuring that any tampering or corruption is detected and rejected before decryption is attempted.
• Screen Shield: Sigil prevents visual eavesdropping by blocking screenshots and hiding the application content in the "Recent Apps" overview (using FLAG_SECURE).
Advanced User Toolkit
• Interactive Onboarding: A comprehensive, guided simulation introduces new users to the zero-trust philosophy, demonstrating live encryption cycles and safe key management without risking real data.
• Secure Keystore: Manage your complex keys securely. You can save, name, and recall encryption keys using the hardware-backed vault, eliminating the need to type long passwords repeatedly.
• Custom Cryptographic Workbench: Users have full manual control to design their own encryption chains. You can add, remove, and reorder layers, selecting from a registry of over 15 industrial and legacy standards.
• System Console: A built-in logging interface provides real-time auditing of the encryption process, including timing metrics and detailed error diagnostics.
• Advanced Theming: Full control over the visual environment, including Material You support, forced Dark Mode, and a custom HSV color engine.
Technical Specifications
• Cryptographic Engine: Powered by CryptoEngine v0.9.0 (utilizing Bouncy Castle) for robust algorithm implementation.
• Key Derivation: Keys are derived using Argon2id with high memory hardening (64MB) combined with SHA-512 pre-hashing to resist GPU-based brute-force attacks.
• Key Separation: The application uses HKDF (HMAC-based Key Derivation Function) to generate mathematically distinct keys for every layer and header from the root secret.
• Supported Algorithms: AES (GCM/CBC), Twofish, Serpent, Camellia, CAST6, RC6, SM4, GOST, SEED, Blowfish, IDEA, CAST5, TEA, and XTEA.
Privacy, Permissions & Open Source
Sigil is a zero-knowledge application committed to transparency.
• Open Source: The complete source code is available for public audit at https://github.com/Animesh-Varma/Sigil, ensuring no hidden backdoors or vulnerabilities.
• Offline Only: It does not require internet access, does not track usage analytics, and does not store data on external servers.
• User Controlled Storage: Data exists only during the active session. Passwords are never stored permanently unless you explicitly save them to the Keystore.
Updates & Changelog
To view the latest version catalog and see exactly what has changed in this release, please visit the Release tab located in the application's side menu.
Sigil Screenshots
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