Sumnvault
A downloadable app for Windows and Android
SumnVault 🔐
Your files. One vault. Fully private.
SumnVault is a modern, cross-platform application for storing sensitive files inside secure, portable and encrypted digital vaults.
Built by Sumnatic, SumnVault is designed around a simple idea:
Your sensitive files should belong to you — not to a cloud service.
A .svault file can contain documents, certificates, images, backups and other files inside a virtual filesystem protected by a password.
✨ Features
🔐 Secure Vaults
Create a .svault file protected by a user-defined password.
Each vault is designed to provide:
- Strong password-based key derivation
- Authenticated encryption
- Encrypted filesystem metadata
- Protection against unauthorized modifications
- Portable, self-contained storage
- Offline-first operation
SumnVault does not require an online account to create or use a vault.
📁 Virtual Filesystem
A vault behaves like its own filesystem.
Personal.svault │ ├── Documents/ │ ├── Identity/ │ │ ├── RG.pdf │ │ └── CPF.pdf │ │ │ └── Certificates/ │ ├── Certificate-01.pdf │ └── Certificate-02.pdf │ ├── Photos/ │ ├── Photo-01.jpg │ └── Photo-02.png │ └── Important/ └── Backup.txt
Inside SumnVault, users can:
- Create folders
- Add files
- Rename files
- Move files
- Replace files
- Delete files
- Rename folders
- Move folders
- Search files
- Export files
All of this happens without exposing the vault's internal contents as ordinary plaintext files.
📦 Portable .svault Format
A SumnVault is represented by a single:
.svault
file.
This makes vaults easy to:
- Back up
- Copy between computers
- Store on external drives
- Transfer between supported devices
- Keep alongside other backups
- Store using third-party cloud storage
The vault format is designed to be independent of the user interface and operating system.
🗜️ Compression
SumnVault can compress data before encryption when doing so provides a meaningful size reduction.
The general pipeline is:
File ↓ Compression ↓ Encryption ↓ .svault
Already-compressed formats can be stored without unnecessary compression.
🧩 Chunk-Based Storage
Vault data is designed around encrypted chunks rather than requiring entire files or entire vaults to be loaded into memory.
This allows SumnVault to scale toward:
- Large files
- Large vaults
- Partial reads
- Streaming operations
- Incremental modifications
The goal is to make a vault containing hundreds of gigabytes fundamentally different from simply loading hundreds of gigabytes into RAM.
🔒 Vault Lock
Vaults can be manually or automatically locked.
When locked, the application stops exposing the vault's contents and requires authentication to access it again.
Planned lock triggers include:
- Manual lock
- Inactivity timeout
- Application exit
- System lock/suspend where supported
- Mobile application lifecycle events
🔍 Search
Search files and folders directly inside the vault.
Initial search focuses on:
- File names
- Folder names
- Paths
SumnVault is designed to avoid creating unnecessary plaintext indexes outside the encrypted vault.
👁️ Secure Preview
SumnVault can preview supported file types without requiring the user to permanently extract them to the operating system filesystem.
Planned/common preview formats include:
- JPEG
- PNG
- WebP
- TXT
- JSON
Preview architecture is designed to minimize unnecessary plaintext temporary files.
💻 Cross-Platform
SumnVault is built with Flutter and Dart and targets:
- 🪟 Windows
- 🐧 Linux
- 🍎 macOS
- 📱 Android
The same .svault should be usable across supported platforms.
For example:
Windows │ ▼ Personal.svault │ ▼ Android │ ▼ macOS │ ▼ Linux
🛡️ Security
Security is the highest priority of SumnVault.
SumnVault does not implement custom cryptographic algorithms.
Instead, it is designed to use established cryptographic primitives and mature implementations.
The conceptual encryption flow is:
User Password │ ▼ Password KDF │ ▼ Encryption Key │ ▼ Authenticated Encryption │ ▼ Encrypted Vault
The architecture is designed around technologies such as:
- Argon2id for password-based key derivation
- AES-256-GCM and/or ChaCha20-Poly1305 for authenticated encryption
- Cryptographically secure random salts and nonces
The final algorithms and parameters should be selected and documented based on the specific implementation and security review.
Important
SumnVault cannot protect data from a fully compromised device while a vault is unlocked.
If malware has control over a computer or phone, it may potentially access information that the user is actively viewing or editing.
SumnVault aims to protect the vault itself against unauthorized access, theft of the .svault file, and unauthorized modification.
🧱 Architecture
SumnVault is designed with a strong separation between the application interface and the vault engine.
Conceptually:
SumnVault │ ┌────────────┴────────────┐ │ │ Flutter UI Core Engine │ │ │ ┌──────────────┼──────────────┐ │ │ │ │ │ Vault Crypto Storage │ │ │ │ │ Metadata KDF/AEAD Chunks │ │ │ │ │ Filesystem Security Compression │ └──── Platform Integration │ ┌─────────┼─────────┐ │ │ │ Windows Linux macOS │ Android
The core should remain independent from Flutter's presentation layer wherever practical.
This allows the vault engine to potentially be reused in the future by:
- CLI tools
- Other interfaces
- Libraries
- Automation
- Additional platforms
📱 Android
Android is treated as a first-class platform.
SumnVault should integrate with modern Android storage APIs rather than assuming unrestricted filesystem access.
This includes support for workflows such as:
- Opening existing
.svaultfiles - Creating vaults
- Importing files
- Exporting files
- Choosing storage locations
- Working with external storage when permitted
- Handling application backgrounding and lifecycle events
Large file operations should use streaming rather than loading entire files into memory.
🖥️ Desktop
On Windows, Linux and macOS, SumnVault provides a desktop-oriented experience with:
- Resizable windows
- Keyboard shortcuts
- Drag-and-drop
- Context menus
- Multi-selection
- File pickers
- Keyboard navigation
- Native filesystem integration
💾 Data Integrity
A corrupted or interrupted save operation should not silently destroy the user's vault.
SumnVault is designed around safe-write principles such as:
Original.svault │ ▼ Temporary.svault │ ▼ Write + Verify │ ▼ Atomic Commit │ ▼ Original.svault
The goal is to ensure that an interrupted operation leaves the previous valid vault intact whenever technically possible.
A future Verify Vault feature will allow users to check:
- Metadata integrity
- Chunk integrity
- Authentication
- Filesystem consistency
- Corrupted blocks
🔑 Password Recovery
SumnVault does not contain a secret master password or universal backdoor.
If a user loses the password to a vault, SumnVault should not be able to simply bypass its encryption.
Optional recovery mechanisms may be introduced in the future, but they must be explicitly configured by the user and designed as cryptographic recovery mechanisms rather than hidden backdoors.
☁️ Cloud Philosophy
Cloud synchronization is not required to use SumnVault.
The fundamental product is local and offline.
🎨 Design Philosophy
SumnVault should feel like premium privacy software.
The design should be:
- Minimal
- Modern
- Professional
- Calm
- Secure
- Intuitive
Avoid unnecessary "hacker" aesthetics.
The visual identity should be consistent with Sumnatic while maintaining its own product identity.
⚠️ Security Status
SumnVault should not be considered independently security-audited until a qualified security review has been performed.
Cryptographic software must be reviewed carefully before being trusted with highly sensitive information.
The project prioritizes:
- Security
- Data integrity
- Reliability
- Cross-platform compatibility
- Performance
- User experience
- Visual design
📄 License
SumnVault
Your files. One vault. Fully private.
Made by Sumnatic 🇧🇷
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