OffCrypt - Android
Open-source
OffCrypt is an offline encryption app for secure text and file encryption using well-known cryptographic algorithms. A secure messaging app that works without an internet connection, with both password-based and RSA public-key encryption (AES-256 and RSA-4096) for Android.
This is a fully offline file encryption app - it does not connect to the internet or collect any user data. All encryption and decryption happens locally on your device. Perfect for journalists, business professionals, and privacy-conscious users who need secure document sharing on Android without cloud dependencies.
Key features include self-destructing messages for Android, secure file deletion, how to encrypt files on Android offline capabilities, and instant RSA 4096 encryption mobile app functionality without account registration. Built for Android in Kotlin with zero data collection policy for private messaging.
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Screenshots
Explore the app interface • Scroll horizontally
Features
Explore all 36+ security features
Modern Cryptography
Encryption algorithms
- RSA-2048 & RSA-4096
- AES-256-GCM encryption
- PBKDF2 key derivation
- HmacSHA256 integrity
- SHA-256 hash functions
- SecureRandom generation
Advanced Security
Protection features
- Digital signatures
- Perfect Forward Secrecy
- Expiring messages
- Burn After Reading
- Version detection
Attack Protection
Defense against sophisticated threats
- Constant-time operations
- Data validation
- Replay attack prevention
- Side-channel protection
- MITM protection
Memory Safety
Complete sensitive data protection
- Data scrubbing (3x overwrite)
- Char/ByteArray wiping
- Aggressive Garbage Collection
- Log buffer clearing
- String pool cleanup
UI Security
Advanced interface protection
- Secure Clipboard
- Lifecycle cleanup
- Background cleanup
- Burn dialog warnings
- Screenshot protection
Features
Advanced cryptographic capabilities
- RSA OAEP + SHA-256
- RSA signature with SHA-512
- Version Byte detection
- Metadata fallback
- Encrypted file export
- Encrypted RSA keystore
Download now
Latest v2.0 available, F-Droid v1.0 coming soon
Free • No ads • Open source • GPL-3.0 License
Complete Your Privacy Protection
You've secured your messages with OffCrypt - now protect your internet connection too
Multi-hop: Channel traffic through additional servers for extra encryption layers
Complete Protection
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