Sometimes it’s not safe. They might be listening. Or you really want to send a message to someone,but don’t want anyone to know. In that case,xda forum member |OP| has an app that might intrigue you. It’s called StegDroid,and it sends a hidden message along with an audio recording to anyone else using the app. It might sound like a harmless voicemail,but contained is a message that is for your eyes only.
The app itself works simply enough. Just launch it and you’ll get a screen similar to the one you see in the screenshot below. Type in your secret message,and then you can move on. The next screen lets you know how many seconds of audio you have to record in order to cover the entire message. The shorter the message,the shorter the audio. When recording the audio it’s probably best to make it sound like a voicemail. After all,everyone gets voicemail,but few people get hidden messages in theirs.
The app will then embed the message into the audio file,which actually takes a few seconds. Then you can test the extraction before you send it off to your secret correspondent. You can send it via Gmail,Bluetooth,or other communications apps you have on your Android. Evernote also came up for me. Gmail appears to be the best way.
As it turns you,the audio file itself doesn’t come into play. It is sent as an attachment in.ogg format,but you never have to play the file if you don’t want to. When you click on the Preview button,you can choose to open the attachment with StegDroid. That will spit out the secret message while not playing the audio. But the communication still appears to be an email with a sound file attachment.
One thing I think was particularly neat about the app is the options. You can choose to send encrypted messages,whereby you set a key that the recipient must also know. Then there’s Paranoid Mode,which wipes all data from the app,including your key,when you close or minimize it. I suppose that if you’re going far enough to send hidden messages that you might as well take this precaution as well.
The app is free,and it’s now available in the Market. So check it out. The only drawback is that you’ll need friends to install the app,too,before it becomes useful.