Vault Explorer

A native Android file manager for VeraCrypt encrypted containers — no PC required.

VaultExplorer lets you mount, browse, and manage VeraCrypt volumes directly on your Android device. Built with Flutter and a custom C++ crypto engine (mbedTLS + FatFs), it decrypts and re-encrypts data fully on-device with zero temporary plaintext files on device storage.

Features

Encryption & Compatibility

Full AES-256-XTS decryption and encryption matching the VeraCrypt standard PBKDF2-SHA512 key derivation with configurable PIM support Compatible with containers created by the desktop VeraCrypt application Supports both FAT32 and exFAT formatted volumes Create new VeraCrypt containers directly from the app

File Management

Browse directories with a breadcrumb navigation bar List view and gallery/grid view with live thumbnails Multi-select with batch operations: copy, move (cut), delete, rename, export Cross-container clipboard — copy or move files between two mounted volumes Import files and entire folder trees from device storage Export files and folders back to device storage Search within the current directory Sort by name, size, or file type

Media Viewer

Built-in image viewer with pinch-to-zoom and double-tap zoom Video and audio playback via the video_player package (FFmpeg-backed via fvp) Slideshow mode with auto-advance Shuffle playlist across current folder or all subfolders recursively Playback controls: speed selection, seek by double-tap, loop, mute Subtitle support (.srt and .vtt files auto-detected alongside video) Image fit modes: best fit, fit to width, fit to height Image prefetch cache for smooth navigation

Android Integration

Exposes mounted containers as a Documents Provider — files appear in Android's system file picker (like Google Photos, Office apps, etc.) Proxy file descriptor streaming — apps read/write directly to the encrypted volume without any plaintext intermediary on disk Supports opening files in external apps via Android's ACTION_VIEW intent

Security & App Settings

Optional master password to lock the app itself on launch Biometric unlock (fingerprint / face) as an alternative to typing the master password Per-container settings: custom display name, saved password (obfuscated), auto-lock timer Auto-lock: automatically dismounts a container after a configurable idle period Password obfuscation for saved credentials (XOR with a key derived from the app's install path) Up to 8 containers can be mounted simultaneously

How It Works

1. Unlock: The app reads the 512-byte VeraCrypt header from the container file, derives the header key via PBKDF2-SHA512, decrypts the header with AES-XTS, and extracts the master key. 2. Mount: FatFs is initialised with custom disk_read/disk_write hooks that transparently decrypt/encrypt 512-byte sectors on every I/O call using the master key. 3. Browse: All file and directory operations go through FatFs over the encrypted disk layer — plaintext data never touches device storage. 4. Stream (Documents Provider): For external apps, a ProxyFileDescriptor is created that serves read/write calls chunk-by-chunk directly through the JNI engine, enabling seamless integration with Android's system file picker.