Flatsonar

Ermis

by Alamahant

Hide content in images or audio

Sandboxed Verified creator GPL-3.0-or-later v1.1.3

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About

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

Permissions

Everything this app can reach outside its sandbox. Nothing here weakens it.

  • inter-process communication (needed for X11)
    --share=ipc
  • network
    --share=network
  • X11 display, only when Wayland is unavailable
    --socket=fallback-x11
  • audio
    --socket=pulseaudio
  • Wayland display
    --socket=wayland
  • GPU acceleration
    --device=dri
  • access to xdg-config/kdeglobals
    --filesystem=xdg-config/kdeglobals:ro
  • talks to com.canonical.AppMenu.Registrar
    --talk-name=com.canonical.AppMenu.Registrar
  • talks to org.kde.kconfig.notify
    --talk-name=org.kde.kconfig.notify
  • talks to org.kde.KGlobalSettings
    --talk-name=org.kde.KGlobalSettings

Who publishes this

The creator demonstrably controls this app id: Flathub verification, the hosting account owns the namespace, or a well-known file on their domain.

  • verified on Flathub: the developer proved they control this app id
    publisher:flathub

Maintenance

Recent activity on the upstream repository, or built and reviewed by Flathub.

No staleness signals: recent activity, or built and reviewed by Flathub.