Top PDF On the (2,2) Visual Multi-Secret Sharing Schemes

Abstract The concept of visual secret sharing (VSS) scheme was first proposed by Noar and Shamir in 1994. This is a technique to divide a secret image into several meaningless images, called shadows, such that certain qualified subsets of shadows can recover the secret image by “eyes”. The main characteristic of VSS schemes is that its decoding process can be perceived directly by the human visual system without the knowledge of cryptography and cryptographic computations. It possesses a special meaning and effect that “the secret codes are visible”.

cryptography - Visual secret sharing - Visual secret sharing schemes Classification code:943 Mechanical and Miscellaneous Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 941 Acoustical and Optical Measuring Instruments - 903 Information Science - 742.2 Photographic Equipment - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 723.5 Computer Applications - 722.2 Computer Peripheral Equipment - 718 Telephone Systems and Related Technologies; Line Communications - 717 Optical Communication - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and

Young-Chang Hou 於 2003 年根據 以往視覺密碼的研究，加上半色調技術及 分色原理 C、M、Y 顏料三原色，再對其 子影像做處理，提出灰階影像和彩色影像 的視覺密碼作法[8]，和傳統上的黑白影像 視覺密碼模型一樣，將機密影像上的每一 個像素擴展至分享影像上的 2×2 區塊，而 區塊中皆保持 2 個色點的狀態。它不但延 續了黑白視覺密碼直接利用視覺系統解 密，無須大量運算的優點，利用在他的方 法上，亦可應用於灰階及彩色影像的製作 上。

DEFINITION 2. A (k, n) NEVSS scheme can be shown as two collections C 0 and C 1 consisting of n λ and n γ n × 1 matrices, respectively. When sharing a white (resp. black) pixel, the dealer first randomly chooses one column matrix in C 0 (resp. C 1 ), and then randomly selects one row of this column matrix to a relative shadow. The chosen matrix defines the gray level of one sub pixel in every one of the n shadows. A NEVSS Scheme is considered valid if the following conditions are met :

to simplify the proposed scheme, we used a simple 3-LSB substitu- tion to embed shadow data into the cover image. Since the corre- sponding shadow data are real numbers, we divided these shadow data into two parts: the integral part and the decimal part, to deal with. Meanwhile, correcting the shadow data to 1 decimal place is able to effectively ensure that the secret image can be reconstructed losslessly. Of course, many variations based on LSB substitution also can be utilized to embed shadow data. It may be possible for these steganographic methods to improve the vi- sual quality of shadow images and enlarge the embedding capac- ity. However, it is beyond the scope of this paper to provide all of the details associated with this issue.

Brickell and Stinson [5] studied a perfect secret sharing scheme for graph-based access structure F where the monotone-increasing access structure F contains the pairs of partic[r]

名: A Scheme for Threshold Multi-Secret Sharing 作者: Chan, C. W.;Chang, C. C 關鍵詞: Access structure;Basis of access structure;The Chinese remainder theorem;Distinctness;Entropy;Idealness;Multi-secret sharing scheme;Perfectness;The Shamir (t, n)-threshold secret sharing scheme;(t, n)-threshold access structure;Threshold multi-secret sharing scheme

5. Conclusion Taken no attention of how to calculate the minimum heating and cooling requirements for a heat- exchanger network, this study presents a sharing strategy for the design of multi-period heat-exchanger network where the required heat exchanger area are known. For a fixed match in different periods, the required heat-exchanger areas are not same. Within the overall objective of investment cost optimization of a multi-period industrial process, it is of great importance to improve the efficiency of recombining heat-exchanger network. This work gives a mathematical programming approach to automatically generate the best equipment sharing structure when there are significant changes in the environment of a plant. This paper shows the several criteria to discern the feasible heat-exchanger network to be recombined. Based on the extensive case studies performed so far, it can be observed that this proposed approach is especially effective for multi-period HEN design problems in which the process conditions vary significantly.

Morillo et al. [19] considered the weighted threshold secret-sharing schemes. This is the case when every participant is given a weight depending on his or her position in an organization. A set of participants is in the access structure if and only if the sum of the weights of all participants in the set is not less than the given threshold. Morillo et al. characterized weighted threshold access structures based on graphs and studied their optimal information rate. Since these access struc- tures are more applicable in real-life situation, an in-depth investigation can have a significant contribution to the applica- tion of secret sharing. We are motivated to construct better secret-sharing schemes for them and have a more detailed analysis of the average information rate of our schemes.

Shiuh-Pyng Shieh ( ) received the M.S. and Ph.D. degrees in electrical engineering from the University of Maryland, College Park, in 1986 and 1991, respectively. He is currently a professor with the Department of Computer Science and Informa- tion Engineering, National Chiao Tung University. From 1988 to 1991, he participated in the design and implementation of the B2 Secure XENIX for IBM, Federal Sector Division, Gaithersburg, Maryland, USA. He is also the designer of the SNP (Secure Net- work Protocols). Since 1994, he has been a consultant for the Com- puter and Communications Laboratory, Industrial Technology Re- search Institute, Taiwan, in the area of network security and dis- tributed operating systems. He is also a consultant for the National Security Bureau, Taiwan.

Abstract Lin and Wu [IEE Proc. Comput. Digit. Tech. 146 (1999) 264] have proposed an efficient ðt; nÞ threshold verifiable multi-secret sharing (VMSS) scheme based on the factorization problem and the discrete logarithm modulo a large composite problem. In their scheme, the dealer can arbitrarily give any set of multiple secrets to be shared, and only one reusable secret shadowis to be kept by every participant. On the other hand, they have claimed that their scheme can provide an efficient solution to the cheating problems between the dealer and any participant. However, He and Wu [IEE Proc.

current technology, the same set of shares can be embedded with many sets of secret messages after one of the shares is rotated at different degrees. However, the used share is rectangle so that only four kinds of angle variation exist when stacking shares. Thus, when intending to embed many sets of confidential messages by using these shares, the angle variation of rotating the shares is limited. This paper proposes an improved (2, 2)-visual secret sharing scheme that adapts circular shares to deal with the limitation of rotating angles in traditional visual

摘要: In this paper, we propose a novel scheme called a self-verifying visual secret sharing scheme, which can be applied to both grayscale and color images. This scheme uses two halftone images. The first, considered to be the host image, is created by directly applying a halftoning technique to the original secret image. The other, regarded as the logo, is generated from the host image by exploiting the interpolation and error diffusion techniques. Because the set of shadows and the reconstructed secret image are generated by simple Boolean operations, no computational complexity and no pixel

reconstructed grayscale image quality than Wang et al.'s scheme without significantly increasing computational complexity, we apply the voting strategy and the least significant bits a[r]

Brick- ell and Stinson studied a perfect secret sharing scheme for a graph-based structure where the monotone-increasing access structure F contains the pairs of p[r]

Abstract A perfect secret-sharing scheme is a method of distributing a secret among a set of participants such that only qualified subsets of participants can recover the secret and the joint shares of the participants in any unqualified subset is statistically independent of the secret. The set of all qualified subsets is called the access structure of the scheme. In a graph-based access structure, each vertex of a graph G represents a participant and each edge of G represents a minimal qualified subset. The information ratio of a perfect secret-sharing scheme is defined as the ratio between the maximum length of the share given to a participant and the length of the secret. The average information ratio is the ratio between the average length of the shares given to the participants and the length of the secret. The infimum of the (average) information ratios of all possible perfect secret-sharing schemes realizing a given access structure is called the (average) information ratio of the access structure. Very few exact values of the (average) information ratio of infinite families of access structures are known. Csirmaz and Tardos have found the information ratio of all trees. Based on their method, we develop our approach to determining the exact values of the average information ratio of access structures based on trees.

Abstract―Multiple secret images sharing scheme deals with the problem that how to secretly distribute several secret images among a group of participants at the same time, and reconstruct these secret images by collecting the shared images or the shares held in qualified subsets. Many studies explore the technique about the secret image sharing, but most of them only can be applied in special access structure or distributed single gray-level image. Shyu and Chen proposed multiple secret images sharing scheme for general access structure in 2008, but there may exists an unqualified subset which can reconstruct the secret images that should not be reconstructed by them in their scheme. Hence, Lee and Juan solved this insecure situation. In the mean time, they also reduced the time complexity, and the sizes of the public image are smaller than those for Shyu and Chen’s scheme. However, the computation of Shyu and Chen’s scheme and Lee and Juan’s scheme still can be reduced, and they both do not achieve the property of multi-use.

We now present an attack on the Hwang–Chen schemes. Let the proxy sign- er P 1 be malicious throughout this section. We will show how P 1 can forge a multi-proxy multi-signature for a secret message M 0 while participating with the other proxy signers in signing another message M.

weight 160, 64, 24, 8, 134, 12, and 3, respectively. Figure 4 is the image revealed by Figs. 3 共a兲 –3 共d兲 , and the revealed image is identical to Fig. 1. Figure 5 compares the execution time in the weighted secret image–sharing phase using Thien and Lin’s 共t=256, n = w i 兲 threshold scheme 3 and our 共t=256, n=1兲 threshold scheme. The two schemes are both tested on an AMD Ath- lon 3500 ⫹ computer with 3GB of RAM. Notably, the ex- ecution time of our sharing algorithm is 7 ⫾3 ms for each of these 255 sets of weights, whereas the execution time increases linearly as the weight value increases in Thien and Lin’s direct and repeated application 共using multiple shadows to simulate weighted feature兲.

Birkhoff interpolation. In their scheme, the secret is shared by a set of participants partitioned into several levels, and the secret data can be reconstructed by satisfying a sequence of threshold require- ments (e.g., it has at least t 0 participants from the highest level, as well as at least t 1 > t 0 participants from the two highest levels and so forth). There are many real-life examples of hierarchical thresh- old schemes. Consider the following example. According to a grad- uate school’s policy, a graduate who wants to apply for a postgraduate position must have letters of recommendation. As- sume that the graduate school’s policy concerning such recom- mendations is that the candidate must have at least two recommendations from professors and at least five recommenda- tions from a combination of professors and associate professors.