SafeFile

Encrypt files and folders locally — no account and no cloud.

SafeFile encrypts files and folders into authenticated .safe vaults with AES-256-GCM and password keys derived through Argon2id, then decrypts them to restore the original content and names. Everything runs locally—your files and passwords are never sent to a remote service.

Highlights

• Run on Windows, Linux, and macOS.
• Encrypt one file, multiple files, or a folder.
• Store a folder as one ZIP vault or one vault per file (PerFile).
• Protect visible filenames with MD5, SHA-256, or AES while retaining the authenticated full original name inside the vault.
• Protect descendant folder names through an encrypted, resumable manifest.
• Exclude selected folder branches from processing.
• See per-file progress, speed, ETA, and Windows taskbar progress.
• Encrypt through a configurable multi-worker pipeline that processes chunks in parallel while preserving their output order for high throughput on modern multi-core CPUs.
• Stream data in bounded chunks instead of loading whole files into memory.
• Preserve existing output unless overwrite is explicitly enabled.
• Encrypt/decrypt text, calculate SHA-256, and generate secure passwords.
• Use Multi-language with Light and Dark themes.
• Search, filter, and export structured application logs.

Using SafeFile

Encrypt

Select one or more files, or a folder, enter a password, and choose a mode:

Source	Mode	Result
One or more files	File	One .safe vault per file
Folder	ZIP	One vault containing the folder
Folder	PerFile	One vault per regular file, preserving structure

Decrypt

Add one vault, multiple vaults, or a folder to scan recursively. The queue shows each vault's name, authenticated original name, size, progress, and result. Large-folder scanning runs away from the UI thread so the window stays responsive.

Protect folder names

The Folder Names page renames descendant directories without changing file names or file contents. Do not delete, edit, rename, or move .safefile-names while names are protected; this manifest is required to restore them.

Tools

The Tools page includes authenticated text encryption/decryption (up to 1,000,000 characters), SHA-256 hashing, and a secure password generator.

Settings

The Settings page controls language and theme, chunk size, worker threads, CPU priority, password policy, Argon2id parameters, and separate encrypted and decrypted output folders. The default output structure is:

Documents/SafeFile/
├── Encrypted/
└── Decrypted/

Security

• AES-256-GCM protects confidentiality and detects modification or corruption.
• Argon2id makes offline password guesses consume time and memory.
• Every vault receives a unique random salt and nonce prefix.
• Passwords and keys are never stored in settings or logs; sensitive buffers are cleared after use.
• Processing stays on the current device and requires no account.

Use a strong, unique password—preferably at least 16 random characters or six independently selected Diceware words. Common phrases, names, dates, reused credentials, and keyboard patterns may be guessed quickly regardless of the encryption algorithm.

Why password strength matters

The table below illustrates the relative strength of truly random passwords. It assumes an extremely aggressive aggregate attack rate of one million Argon2id guesses per second and finding the password halfway through the search space on average. These figures are intentionally conservative estimates—not benchmarks or guarantees—and do not apply to human-created or reused passwords.

Truly random password	Approximate average time
8 lowercase letters	about 29 hours
8 letters + digits	about 3.5 years
10 letters + digits	about 13,000 years
12 letters + digits	about 51 million years
16 letters + digits	about 756 trillion years

Limitations

• Forgotten passwords cannot be recovered.
• Malware or keyloggers on a compromised device can capture passwords or plaintext.
• Secure deletion cannot be guaranteed on SSDs, snapshots, or copy-on-write filesystems.
• SafeFile has not yet undergone an independent professional security audit.

For the vault format, nonce construction, validation rules, API contracts, and pipeline details, read the SafeFile.Core Technical Guide. See also RFC 9106 and the OWASP Cryptographic Storage Cheat Sheet.

Disclaimer

SafeFile is provided for lawful purposes only. You are solely responsible for ensuring that your use of the application complies with all applicable laws and regulations. The developers and contributors do not endorse or accept responsibility for any illegal, unauthorized, or harmful use of SafeFile.

The software is provided “as is,” without warranties of any kind. To the fullest extent permitted by law, the developers and contributors are not liable for data loss, corrupted files, failed encryption or decryption, forgotten passwords, hardware or software failures, incompatibilities, or any other direct or indirect damages resulting from the use of this application.

Build from source

Install the .NET 10 SDK. The project is currently built and validated primarily with the Windows toolchain.

git clone https://github.com/kevinxvu/SafeFile
cd SafeFile
dotnet restore SafeFile.slnx
dotnet build SafeFile.slnx
dotnet run --project SafeFile/SafeFile.csproj

From WSL using the Windows .NET SDK:

dotnet.exe build SafeFile.slnx

Project structure

SafeFile.Core/          Cryptography and file-processing layer
SafeFile/               Avalonia desktop application
SafeFile.Core.Tests/    Regression tests
SafeFile.slnx           Solution

Contributing

Issues, security reviews, translations, tests, documentation, and focused pull requests are welcome. Keep SafeFile.Core independent from Avalonia, never log sensitive data, preserve output unless overwrite is explicit, keep English and Vietnamese resources synchronized, and build the full solution before submitting changes.

For suspected vulnerabilities, prefer the repository's private security reporting channel over publishing exploit details in a public issue.

License

SafeFile is available under the MIT License.