Ermis is a cross-platform steganography application that allows you to hide and extract secret data within digital media files. Named after the Greek god of messages and communication, Ermis enables covert communication through innocent-looking image and audio files.
Image Steganography:
- Hide data in PNG, JPG, and BMP images using LSB (Least Significant Bit) techniques
- Live preview of original and modified images with side-by-side comparison
- PRT Artistic Mode: Specialized visual steganography for camera-scannable codes
- Real-time capacity indicator showing available hiding space
Audio Steganography:
- Support for WAV, MP3, FLAC, and OGG audio files
- Automatic conversion of non-WAV files using FFmpeg
- Built-in audio player with play/pause/stop and volume controls
- Metadata extraction for accurate capacity calculation
Data Handling:
- Text input for hiding plain messages with UTF-8 encoding
- File input for hiding any file type with filename preservation
- Smart marker system (0x00 for text, length byte for files)
- Automatic detection of data type during extraction
Security Features:
- Optional AES encryption with passphrase protection
- ENCR marker for automatic encrypted data detection
- Passphrase memory during current session
- Secure extraction with decryption prompts
User Interface:
- Dual-tab interface for hiding and extracting data
- Drag and drop support for both images and audio files
- Clipboard integration for one-click text copying
- Image preview highlighting with file path display
- Camera integration for scanning PRT artistic codes
Screenshots
Observed history
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No observed changes yet.
The initial import establishes a baseline. Future version changes will appear here.
Browse the app catalogue →Upstream releases
Release notes supplied by the developer. These dates are not Flathub package publication times.
1.1.319 Jul 2026
UPnP port management and NAT traversal:
- UPnP Port Manager for automatic router configuration
- Open and close TCP/UDP ports without manual forwarding
- List active UPnP mappings (supports most routers)
- Test router connectivity to verify UPnP availability
- Local port tracking for routers without listing support
- Auto-close all open ports on application exit
- Bundled miniupnpc library for Flatpak builds
- Flatpak sandbox compatibility with proper rpath config
1.1.211 Jul 2026
ELF binary and PDF steganography expansion:
- ELF binary steganography for Linux and BSD systems
- Hide data in ELF executables using .debug_types section
- Binary remains fully functional after embedding
- Bundled objcopy and readelf tools (no external dependencies)
- FNAM flag preserves original filename on extraction
- ENCR flag for automatic encrypted payload detection
- AES-256-CBC encryption with passphrase support
- ELF magic byte validation (0x7F E L F)
- PDF steganography with object stream embedding
- FlateDecode compression for efficient PDF storage
- PDF capacity calculation and validation
- Filename preservation for PDF binary transfers
- Auto-save for extracted files with original name
1.1.120 Apr 2026
PDF and distributed steganography expansion:
- PDF steganography with object stream embedding and encryption
- Distributed steganography via Wikipedia pointer maps
- Filename preservation for binary file transfers (FNAM flag)
- Auto-detection of encrypted payloads with passphrase prompt
- Binary file auto-save with timestamp naming
- Theme-aware info buttons across all steganography dialogs
- Fixed dark theme toggle persistence on application restart
- Fixed Linux file dialogs hiding binary/system files
- Network steganography coordination warnings added
1.1.027 Mar 2026
Network and text steganography expansion:
- Network steganography via ICMP, DNS, UDP, HTTP/TLS protocols
- Zero-width character text steganography with binary encoding
- AES-256-CBC encryption with PBKDF2 key derivation
- Multi-layer security with composable steganography modes
- Reliable packet delivery with sliding window protocol
- IP filtering with whitelist/blacklist and CIDR support
- File and plain text transfer with progress tracking
- Text steganography UI with capacity calculator
- Automatic text/binary format detection on extraction
- Dark theme and dark-light theme toggle
- User data folder shortcut creation feature