2015 International Conference on Computers, Communications, and Systems
An Information Hiding System Based on High Frame Rate Video
Peng Gu2, Jie Yuan1,2 1
Yao Ding1,*, Yinan Zhang1
Jinling College, Nanjing University, Nanjing, China, 210089
Abstract—There are two drawbacks in conventional steganography technology. First, hidden messages cannot be observed by human eyes. Second, decryption process is so complex that it is hard to reach real-time requirements. In this article, it is expected to find a new method, which is simple, fast and secure. Taking these principles into account, we establish a confidential display system based on high refresh rate display. The system consists of a FPGA, a high refresh rate screen and shutter glasses. Under the control of FPGA, useful frames are submerged in a large number of other redundant frames. Useful frames, together with redundant frames, display on the high refresh rate screen. Because of the redundant in-formation’s interference, it is difficult for the human eyes to find out the useful information while it’s easy to pick up useful information through the high-speed shutter glasses, which can exclude the redundant information.
2
School of Electronic Science and Engineering, Nanjing University, Nanjing, China, 210093 * email:
[email protected]
operated to alternate between substantially orthogonal states of polarization and cause the display to rapidly alternate between a normal positive and inverted negative image, creating a combined neutral image that in indecipherable to the naked eye. Shutter eyewear synchronized with the variable polarizer is used to extract the positive image for viewing by an intended viewer.
Keywords-Information hiding; High rate; confidential display
I.
INTRODUCTION
We are always worried about our privacy in public places as our screens are exposed to others. It may also happen that the information on the self-service terminals raises other people’s attention while we are withdrawing money. We cannot just cover their eyes when we have something really private to hide. These conditions prove that a simple, fast and secure method is badly needed to reduce the attention to our privacy in public, which is our goal of this article. Currently, there are mainly two technical methods to achieve confidential display as discussed in [1]: A. Adjustable Viewing-angle Display: The LCD (liquid crystal display) screen proposed by Hashimoto in [2] can change mode between wide-viewing-angle and narrow-viewing-angle. As shown in Fig.1, users can choose wide-viewing-angle and narrow-viewing-angle in different situations. When it is working in the narrow-viewing-angle mode, the screen only allows people to view in the narrow angle. However, its narrow viewing angle is also a drawback. B. Polarized Glasses: As discussed in [3], there is a kind of display apparatus having a pair of polarizers. As shown in Fig.2, one of the polarizers being a variable polarizer which is independently
146
Figure 1. Adjustable viewing-angle display
Figure 2. Confidential system based on polarized glasses
They are both popular in practical application but their security features are not good enough. In theoretical studies, steganography has emerged as a new method in information hiding. As discussed in [4], the most important goal of steganography, as a branch of
978-1-4673-9754-4/15/$31.00 ©2015 IEEE
information hiding in Fig.3, is confidentiality, which is also called imperceptibility, invisibility or inaudibility as discussed in [5-6].
We call frames with useful information useful frames while frames with redundant information redundant frames. Due to the interference of a large number of redundant frames and high frame rate, human eyes cannot perceive the useful information. In order to assure security, the system also use a random number generator to control the display of useful frames or redundant frames. We will explain the principle of it in the following text.
Figure 3. Branch of steganography
Focusing on the image steganography, the techniques in this domain can be divided into two groups: those in the Image Domain and those in the Transform Domain as discussed in [7-9]. In the image domain, least significant bit (LSB) insertion as discussed in [10] is a common method, simple approach to embed-ding information in a cover image as discussed in [11]. However, this traditional technology’s total amount of hidden information is not enough because of inadequacy of their media’s redundant data amount. For an 800 × 600 pixel image using 24 bit color, the image can only contain a total amount of 180,000 bytes of secret data as discussed in [12]. Actually, the secret information is often in the transform domain of the carrier taking more security into consideration, which make the secret information invisible after decryption. The method of transform domain steganography, mainly including JSteg, F3, F4 and F5 algorithms, is to embed secret data in the transform coefficients, which meets the requirements of both imperceptivity and robustness as discussed in [13]. These methods are too complex that it is hard to reach real-time requirements. There are also some confidential display system. In [1], Zeng proposed that inverse images of original ones can help conceal the information. The most important disadvantage of mentioned methods is that they are not secure under the situation that we can take pictures to get the information easily. To summery, we need a simple, fast and secure method to reduce the attention to our screens. II. PRINCIPLE OF THE PROPOSED SYSTEM A. Encryption and Decryption Process To make the secret information visible and display real-time, the system we proposed puts useful information in a lot of redundant information and then display them on a high refresh rate screen at a high frame rate in the encryption process as discussed in [14]. Fig.4 shows the process of encryption.
Figure 5. Decryption process
In the decryption process as shown in Fig.5, we use a pair of high-speed shutter glasses synchronized with the screen, which is on during the useful frames and is off other time. So, we are able to pick up useful frames. In this way, the encryption and decryption process is completed. The method is simple and secure. And the system can meet real-time requirement if we use high-speed control device. Therefore, the problems mentioned can be solved well. B. Choice of redundant frames There are some key points which may decide the performance of the whole system [15]. One is the choice of redundant frames. Another is the location of useful frames. When it comes to the choice of redundant frames, two different methods should be taken into consideration [16]. If we make the final vision a normal picture, that means redundant frames should be one picture related to useful frame, which may decrease the amount of hidden data and also leak secret information because of the blurred shadow on the picture. To cover useful frames, we really need different pictures to have average gray value on each pixel. Another method use pictures uncorrelated to useful frames. Taking variability of useful frames into consideration, we use different sets of redundant frames to conceal different useful frames. If not, we can feel the flash as well. In our experiment, we can take photo of frames on the screen. So, we choose some pictures having some ‘fake information’ in order to protect real information from the attack of camera. Another key point is the location of useful frames. If the location of useful frames is fixed, the control signal of the glasses is period, which make it easy to be synchronized without any difficulty. Take these into consideration, we
Figure 4. Encryption process
147
employ one random number generator to decide whether the current frame is useful or redundant. The way we use it is just like Fig.6.
Second, confusing useful frames with redundant frames. It’s just like the encryption process embedding useful information in the carrier. Schematic diagram is shown in Fig.8:
Figure 6. Random number sequence Figure 8. Confusing useful frames
Linear congruential generator we used can generate random number in the space of one-dimension and reflects good randomness [17], which makes it the most popular way to generate random number. Recurrence formula of the method is as following: X i (a X i c) mod( m)
It is similar to the real random number columns and the correlation between the numbers are quite small. In the system, we actually use two random number generators. One is to determine whether we use useful frames or redundant frames, another is to determine which redundant frame will be chosen. III. IMPLEMENT AND ANALYZE A. Hardware Implement The system we established mainly includes four parts: LED screen, FPGA control module, high-speed shutter glasses and user interaction module. Different parts are combined by an adapter board, which is placed in a metal box to reduce external effects. The whole framework map is as Fig.7:
Third, displaying frames on the screen. Forth, picking up useful frames. We turn the glasses on during the useful frames and off the redundant frames. B. Evaluation System In regard to the test program of the confidential display system, there is no absolute objective evaluation system. The subjective evaluation method depends on the observers ‘assessment of the pictures’ quality. The method is based on human visual system and uses MOS (Mean Opinion Score) as discussed in [18]. The formula of the MOS is as the following. n
S
n s i 1 n
i
i
n i 1
i
where Si is the score of i category while ni is the score of the ith person’s assessment. Actually, we have 25 observers, who judge the quality of the pictures through the glasses, to make the assessment. For each test entry, observers score twice. So each assessment account for 2 percent. Depending on different weight, the method transforms different evaluation levels, such as fine, good, general and poor, to quantified scores. TABLE I. EVALUATION LEVELS Test entry
Figure 7. Hardware block diagram
The work steps are as following: First, transporting useful frames to FPGA control device.
148
Single person static pictures test Single person dynamic pictures test Multiplayer static pictures test Multiplayer dynamic pictures test 3D performance
Evaluation level (weight) Cannot aware of hidden pictures without glasses (2%) Cannot aware of hidden pictures without glasses (2%) Cannot aware of hidden pictures without glasses (2%) Cannot aware of hidden pictures without glasses (2%) Fine Good (2%) (1.5%)
Aware of hidden pictures without glasses (0%) Aware of hidden pictures without glasses (0%) Aware of hidden pictures without glasses (0%) Aware of hidden pictures without glasses (0%) General Poor (1%) (0.5%)
The relationship of different evaluation levels and corresponding scores is as Table I and Table II.
Science Foundation of Jiangsu Province (Grant Number. BK20131280).
C. Test Data In the test, we choose different parameter ‘P’, which is the numbers of a cycle display, to find the best result.
REFERENCES [1] [2]
TABLE II. HIDDEN INFORMATION PERFORMANCE Result P=20
Result P=15
Result P=10
Single person static Pictures hiding test
100%
100%
100%
Single person dynamic Pictures hiding test
100%
98%
92%
Multiplayer static Pictures hiding test
100%
100%
100%
Multiplayer static pictures Hiding test
100%
90%
82%
3D performance
99%
95%
95%
Test entry
[3]
[4]
[5] [6]
D. Result Analysis In the test, we choose different parameter ‘P’, which is the numbers of a cycle display, to find the best result. The test data shown above proves that the performance of hiding information is good with enough security while it has big advantage on the display effect. Table 5.3 proves that the parameter ‘P’ should be larger than 10 or its dynamic performance will have a sharp decline. In practical use, in order to get better vision through the glasses and have enough security, the parameter ‘P’ should in the range of 15 to 20. In summary, the system has meted the requirements of the confidential display. Through realization of the system, we have proved it feasible and practical that useful information can be hidden on the screen by redundant information.
[7]
[8]
[9] [10]
[11]
[12]
[13]
IV. CONCLUSION Compared with conventional technology in the whole region of information hiding, the system we proposed is simple and fast, and the hidden information is visible in real time. Different from some other confidential display system, our system enjoys a better sense of security based on high frame rate and random number generator. These advantages make our privacy safer in public place. Future work includes making synchronization wireless and encrypting synchronized signal. This can free our position during experiencing the system. Of course, the system has a wide range of applications. It can be used on every self-service terminal, personal laptop or real-time video and it will be a good realization of information hiding. ACKNOWLEDGEMENT This work was supported by National Natural Science Foundation of China (Grant Numbers 61201425), Natural
[14]
[15]
[16]
[17]
[18]
Zeng Xiongbing, Chen Yong, Lu Xiaoling, Yang Jianjun. "Encoded Confidential Display." Video Engineering ,2007,31(12) :pp43-45. Okamoto Masayuki, Yamada Nobuaki, Kozaki Shuichi, Hashimoto Yoshito, Mizushima Shigeaki, “Liquid crystal display apparatus having adjustable viewing angle characteristics.” U.S. Patent 5, 1999-3-2, pp.877, 829. Struyk David A., “LCD-based confidential viewing apparatus utilizing auto-inversion masking.” U.S. Patent 7, 2010-9-7, pp.791, 686. Petitcolas, Fabien A.P., Anderson, R.J., Kuhn, M.G., “Information Hiding--A Survey.”Proceedings of the IEEE.1999, 87(7):pp.1062-1077. Provos N, Honeyman P, “Hide and seek: An introduction to steganography.” IEEE Security & Privacy, 2003, Vol.1. pp.32-44. Ge Huayong, Huang Mingsheng, Wang Qian, “Steganography and steganalysis based on digital image.” Image and Signal Processing (CISP), 2011 4th International, 2011,Vol.1. pp252-255 Abbas Cheddad, Joan Condell, Kevin Curran, Paul McKevitt , “Digital image steganography: Survey and analysis of current methods.” Signal Processing. 2010, 90(3): pp. 727-752. Haiping Huang, Shichao Huang, Jiutian Chen, Ruchuan Wang, Jianhui Xiong, “An image information hiding algorithm based on grey system theory.” Int. J. Commun. Syst., 2014, Vol.27 (10) pp.2426-2442 doi:10.1002/dac.2551 Neil F. Johnson, Sushil Jajodia . “Exploring Steganography, Seeing the Unseen.” IEEE Computer, 1998, Vol.31 pp.26-34 Soumyendu Das, Subhendu Das, Bijoy Bandyopadhyay, Sugata Sanyal, “Steganography and Steganalysis: Different Approaches.” CoRR, 2011, Vol.abs/1111.3 Ali K. Hmood, B.B. Zaidan, A.A. Zaidan, Hamid A. Jalab , “An Overview on Hiding Information Technique in Images.” Journal of Applied Sciences, 2010, Vol.10 (18), pp.2094. Zoran Duric, Michael Jacobs, Sushil Jajodia, “Information Hiding: Steganography and Steganalysis”, Handbook of Statistics,2005, Vol.24 , pp.171-187. Ming Chen; Ru Zhang; Xinxin Niu; Yixian Yang, “Analysis of Current Steganography Tools: Classifications & Features.” Intelligent Information Hiding and Multimedia Signal Processing, 2006. IIH-MSP'06. International. IEEE, 2006, pp.384-387. Ryan Harkins, Eric Weber, Andrew Westmeyer “Encryption Schemes using Finite Frames and Hadamard Arrays” CoRR, 2004, Vol.cs.CR/0405. Md. Al Mehedi Hasan, Mohammed Nasser, Biprodip Pal, Shamim Ahmad “Support Vector Machine and Random Forest Modeling for Intrusion Detection System (IDS)” Journal of Intelligent Learning Systems and Applications, 2014, Vol.06 (01), pp.45-52 Steven P. Blurton, Mark W. Greenlee, Matthias Gondan “Multisensory processing of redundant information in go/no-go and choice responses” Attention, Perception,& Psychophysics, 2014, Vol.76 (4), pp.1212-1233 Michael Mascagni, Hongmei Chi “Parallel linear congruential generators with Sophie–Germain moduli” Parallel Computing, 2004, Vol.30 (11), pp.1217-1231 Mahesh Viswanathan, Madhubalan Viswanathan “Measuring speech quality for text-to-speech systems: development and assessment of a modified mean opinion score (MOS) scale” Computer Speech & Language, 2004, Vol.19 (1), pp.55-83
149
