15 Free Steganography Apps for Mobile Devices

Hide messages within innocent-looking photos and audio files from your phone or tablet.

steganography

Steganography has been used for centuries to hide secret messages in places nobody would think to look, and the art has advanced to include using digital files as places of concealment. Secrets can be embedded within photo and audio files by replacing the least essential code with bits of the hidden data. Developers have come up with a wealth of applications that can do this work from mobile devices and many of them are free. Here is a sampling of 15 such apps available for Apple, Android and Microsoft devices.

Lakeside Llama

Concealment: From Lakeside Llama this iOS app lets you take a picture and hide a secret message inside of the image (up to three hidden images). These images can then be stored in the in-app photo library, the device  photo library, iMessage (iOS 5) or be emailed directly to whomever one is sending the message to, the company says.

Hide It In

Hide It In: Hide It In is an app that hides an image taken with your iPhone camera into another seemingly innocuous image from your photo library that can be sent by email. Select the cover image and take a picture with your phone.  Developed by Jorge Blasco, Hide It In features among other things, AES encryption to ensure that even if the presence of a secret message is suspected, only password holders will be able to recover the hidden image.

Acoustic Picture Transmitter

Acoustic Picture Transmitter: According to developer Dominik Siebold, this app lets you transmit and receive images acoustically. To do this each column of the selected message gets transformed by a Fast Fourier Transform and outputted through iPhones speaker. On the receiving iOS-device the received audio is visualized by a spectrogram and the incoming images become visible. You can use this app for example to transmit images very easily over a phone or to put images in every kind of audio recording.

Spy Pix

Spy Pix: This iPhone app uses steganography to hide one image inside of a decoy image. To a casual viewer, only the decoy image is seen. However, for a veteran spy, the image can be decoded with Spy Pix to reveal the hidden message, the company says.

Steg-O-Matic

Steg-O-Matic: According to developer BlueJava, the Steg-O-Matic app hides the secret message in an image and offers tools for sending the image via email, social media or post it on a public blog. Only those intended to read the secret will know to look for it and know how to retrieve it.

DeepSound

DeepSound: This Windows 8 app hides secret data in audio files that can be sent to the intended recipient. The file will play without any discernable distortion to the ear, but the hidden data does increase the size of the file. The secret can be data of any type, such as text, images and video. A DeepSound file browser extracts the hidden message.

Secret Tidings

Secret Tidings: For Android and Windows 8, Secret Tidings conceals messages within photos, guiding the user through the process of choosing or creating the carrier photo, sending it and decrypting it. It has icons for sending the images to social media sites as well as emailing or texting them.

Stegais

Stegais: With this Windows Phone 8/Android app users can hide the message in a photo that is taken from the phone’s camera or from a photo library. The steganographic image can be sent or stored, so it could be used as a way to conceal information on the same device that creates the cover file.

Steganography+

Steganography+: Also for Windows Phone 8, Steganography+ can store files in SkyDrive that are named MyEnSteganography+ and MyDeSteganography+. This makes it possible to remove the cover file from the phone entirely once the message has been embedded. The hidden files on images stored in SkyDrive can’t be opened directly in SkyDrive. They must be downloaded to the phone first.

Magic Picture

Magic Picture: This Windows Phone 8 application has a simple user interface to choose a picture, create the message to be embedded and then save it. The altered images can be emailed. The author says he is working on a new version that will encrypt the message embedded in the picture. He also says, “NOTE: There isn't Magic!!! Only Steganography ;-)”.

DaVinci Secret Message

DaVinci Secret Message: An Android app, DaVinci Secret Message can password protect the message hidden within an image, giving another level of security. It also gives the option to define the size of the final image, making it more difficult to suspect whether a carrier image contains a secret based on its size difference from the original image file.

PixelKnot

PixelKnot: Created by developers in the Guardian Project, PixelKnot for Android uses the F5 steganography algorithm that makes hidden messages more secure from statistical attacks by uniformly spreading around the changes the secret message makes to the original image. This also boosts the size of the embedded message without increasing the risk of discovery.

Steganographia

Steganographia: This Android app offers eight levels of robustness for the hidden message. The idea is to make the message more likely to survive intact even when the image carrying it is recompressed for display on sites such as Facebook and Twitter. The more robust the message, the larger it is and so the more likely that it will alter the appearance of the carrier image.

Secret Letter

Secret Letter: This new Android application hides messages in stored images or photos taken from a camera. They can be emailed and the secrets extracted by the recipient.

Incognito

Incognito: This Android application utilizes both steganography and cryptography to hide different types of information such as text messages, pdf files, images, music files, etc. within images without changing the outward appearance of the image. The publishers recommend it for use by business people worried about competitors spying.