A Novel Behavior Steganography Model Based on Secret Sharing

1. Introduction

Information hiding is an art of hiding secret messages in another seemingly innocuous carrier (Johnson, Duric & Jajodia, 2012), which is a powerful technique that can enhance security in data transferring and archiving. Throughout history, a multitude of methods have been used to hide information. With the development of the Internet and other new technologies, digital steganography technique, which is used to embed the secret message into digital multimedia, is gradually rising. It has developed a strong basis for the area of steganography with a growing number of applications for digital fields like digital rights management, covert communications, annotation etc. So far, various researches on steganography have been carried out on storage media, such as text, image, audio, and video.

Compared with security technologies, such as encryption and secret sharing, the aim of information hiding conceals the existence of secret messages to ensure that the secret information transmission unbeknown. Since when an attacker doesn’t know the existence of secret messages, he won’t generate the idea of attacking it. Moreover, the information hiding method must also ensure the successful extraction of the secret information. Thus, there are three metrics that evaluate a steganography scheme (Divya & Reddy):

• 1.

  Imperceptibility evaluates how well a secret message is embedded into the carrier. The difference between carrier after hiding and before hiding should remain negligible.

• 2.

  Robustness indicates the ability of secret messages to resist against attacks.

• 3.

  Capacity means the amount of secret information that can be embedded into the original carrier without affecting the perceptual quality of carrier.

The traditional steganography is to hide the secret message embedded in the digital multimedia, and in recent years, coverless steganography and behavior steganography gradually rise. So, this paper intends to propose a novel behavior steganography model based on the random selection behavior of secret sharing.

In many SIS schemes, shadow images need to be generated according to some random numbers whose values have little effect on the sharing and recovery of secret images and how to choose a random number is controllable. So, the selection of random numbers, this behavior, can be considered as a way of steganography. On the basis of this idea, this paper presents a behavior steganography model based on secret image sharing. In the embedding phase, the random selection behavior is employed to hide the secret message. In the extraction phase, when the secret image is recovered from shadow images, the secret messages can also be extracted successfully. Experimental results and analyses demonstrate the effectiveness of the proposed model. In comparison with traditional steganography methods, our contributions are summarized as follows:

• 1.

  First, we explore the behavior steganography model based on secret sharing. This model combines information hiding and secret sharing, and secret messages are hidden in parallel with secret image sharing, which means that in a communication process, two covert channels are opened;

• 2.

  There are lots of random elements participating in the secret sharing process. And we embed secret messages in random elements, which can provide a large amount of hidden capacity;

• 3.

  The steganography process does not require the original carrier, and secret messages are just embedded during the secret sharing process. So, the risk of being analyzed reversibly is reduced because of no comparison with original carrier. In addition, the shadow image obtained by this method is basically the same as that obtained by the original method;

• 4.

  Traditional steganography does not have loss tolerance. Our scheme based on secret sharing makes up the deficiency of steganography. Even if part of the shadow images is lost, secret messages can still be successfully extracted;

• 5.

  This model is applicable to a variety of secret image sharing algorithms. The two schemes proposed in this paper are just examples of the combination of our model and specific secret sharing algorithms, and more secret sharing algorithms can be applied to this model.