Lightweight Steganography on Smartphones

Steganography is an historical technique to send secret messages embedded into carrier messages. The introduction of computers provided very sophisticated techniques to create carrier messages, to embed the secret, and to detect steganographic messages. The smartphone devices are both popular and ubiquitous, and they can be used as an ``all-in-one'' device for steganography.The users can shoot photos, and use them as carrier message. By means of the computational capacity of the smartphones, the user can also embed and retrieve small messages into the photos stored into the device. Moreover, the user can securely communicate its secrets by means of sending and receiving MMS messages. The Multimedia Messaging Service, MMS, is a common technique to exchange images in the actual scenario of cellular telephony. In this paper we show the results of preliminary studies to test the feasibility of such an approach.