• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권5호
• /
• pp.1785-1800
• /
• 2014

In 2011, Chen and Wu proposed their method of sharing n secret images to n+1 shadow images through the concept of a Boolean-based Visual Secret Sharing (VSS) method. However, the shadow images produced by this method are not equally important. If the participant who owns an important shadow image does not want to cooperate with other participants, most secret images can not be reconstructed. In the proposed method, the relationship between the shadows images and secret images are designed in a circular way mostly. Each shadow image only relates to two secret images. This means that if one participant refuses to cooperate with other participants, there are only two secret images which can not be reconstructed. Moreover, our proposed method only needs to produce n shadow images and n secret images can be shared to them.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권7호
• /
• pp.2862-2878
• /
• 2020

Data Security is the most challenging area in Internet communication, where most of the secret sharing schemes are proposed for binary images. But still it lacks in providing security for data communication, especially in image transmission. Traditional visual cryptography scheme generate meaningless diwies and the reconstruction phase leads to quality degradation over the secret image. In this work, an intelligent two dimensional secret share construction scheme is proposed. A secret image is expanded into n diwies with the choice of scheme selection. By Stacking all the qualified diwies to revert the secret image without content loss and less than s^* - 1 shares could not reveal any information about the secret image. The experimental results emphasize that the proposed secret share scheme is highly secured for image transmission.

• 정보처리학회논문지C
• /
• 제11C권5호
• /
• pp.585-594
• /
• 2004

다수의 사업자간에 공동키를 기반으로 서비스를 제공할 경우, 이에 사용되는 마스터키를 참여 사업자간에 적절하게 분배하여 관리할 필요가 있다. 본 논문에서는 하나의 비밀(secret)을 다수의 참가자에게 분배한 후, 비밀정보를 복원 필요시 참가자 전원 또는 참가자 집단 내에서의 특정 허가된 참가자만이 비밀을 복원할 수 있는 비밀분산법을 이용하여 마스터 키(master key)를 효율적이고 안전하게 관리할 수 있는 비밀분산 시스템을 제안한다. 제안한 시스템은 비밀정보의 안전한 저장과 참가자의 신원 인증을 위해 스마트카드(smart card) 매체를 이용하며, (t, t)과 (k, n)-임계치 비밀분산법을 조합하여 참가자의 소속 그룹(group) 또는 그룹 내에서의 보안권한(security level)에 따라 비밀정보를 분산 및 복원을 가능하도록 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권10호
• /
• pp.3557-3571
• /
• 2014

We develop a secret key generation scheme using phase estimation in ultra-wideband (UWB) wireless fading channels. Based on the reciprocity theorem, two terminals extract the phase of the channel as a common random source to generate secret bits. Moreover, we study the secret key rate by a pair of nodes observing correlated sources and communicating to achieve secret key agreement over public communication channels. As our main results, we establish a more practical upper bound from Cramer-Rao bound (CRB) and compare it with a universally theoretical upper bound on the shared maximum key rate from mutual information of correlated random sources. Derivation and numerical examples are presented to demonstrate the bound. Simulation studies are also provided to validate feasibility and efficiency of the proposed scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권12호
• /
• pp.4552-4567
• /
• 2014

A (n,t,n) secret sharing scheme is to share a secret among n group members, where each member also plays a role of a dealer,and any t shares can be used to recover the secret. In this paper, we propose a strong (k,t,n) verifiable multi-secret sharing scheme, where any k out of n participants operate as dealers. The scheme realizes both threshold structure and adversary structure simultaneously, and removes a trusted third party. The secret reconstruction phase is performed using an additive homomorphism for decreasing the storage cost. Meanwhile, the scheme achieves the pre-verification property in the sense that any participant doesn't need to reveal any information about real master shares in the verification phase. We compare our proposal with the previous (n,t,n) secret sharing schemes from the perspectives of what kinds of access structures they achieve, what kinds of functionalities they support and whether heavy storage cost for secret share is required. Then it shows that our scheme takes the following advantages: (a) realizing the adversary structure, (b) allowing any k out of n participants to operate as dealers, (c) small sized secret share. Moreover, our proposed scheme is a favorable candidate to be used in many applications, such as secure multi-party computation and privacy preserving data mining, etc.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권10호
• /
• pp.5144-5160
• /
• 2019

Secret sharing is an effective way of protecting secret messages. However, the traditional secret sharing schemes are considered meaningless due to malicious people attention which might raise risks. To overcome the weakness, this paper presents an effective secret sharing scheme with the functionality of cheater identification, based on meaningful QR code. The secret message will be split and concealed in the padding region of cover QR codes with the assistance of Latin square and it can be completely restored when all the involved participants cooperate. The concealing strategy exploits the characteristic of Reed-Solomon (RS) code to ensure the strong robustness of generated QR code pseudo-shares. The meaningful QR code pseudo-shares help to reduce the curious of unrelated persons. Some experiments were done to evaluate the performance of proposed scheme. The results showed that the proposed scheme is feasible, efficient and secure compared to the other existing schemes. It also achieves a higher secret payload and maintains stronger robustness.

• 한국정보과학회논문지:시스템및이론
• /
• 제30권9호
• /
• pp.487-493
• /
• 2003

비밀분산법이란 하나의 비밀정보(Secret)를 분산시켜 다수의 참가자에게 공유시키고, 필요시 허가된 참가자 부분집합만이 비밀정보를 복원할 수 있는 암호 프로토콜이다 비밀정보 복원을 위한 다양한 접근구조를 반영하는 비밀분산법이 제안되었는데, 본 논문에서는 계층구조에 적용 가능하고 재사용이 가능한 새로운 비밀분산법을 제안한다. 즉. 참가자들은 계층구조의 상위 레벨부터 비밀정보 복원에 대한 우선권을 갖고, 상위 레벨에 속하는 참가자들이 부재 시에는 하위 레벨에 속하는 참가자들은 위임티켓 (delegation ticket)을 전송하여 비밀정보의 복원 권한을 위임할 수 있다 또한, 각 참가자는 초기에 생성한 하나의 비밀조각으로 서로 다른 비밀정보를 복원하는데 참석할 수 있도록 함으로써, 계층그룹에서 비밀 조각의 재사용이 가능하도록 한다.

• 한국군사과학기술학회지
• /
• 제14권3호
• /
• pp.482-491
• /
• 2011

The purpose of this study is to design and implement a 2-level secret information transmission system which can be used for information hiding of images transmitted over various IT communication media. To increase the robustness of the hiding power, we combined the steganography method which inserts secret object into cover object to hide the very fact of information hiding itself, and the preprocessing stage to encrypt the secret object before the stego-insertion stage. As a result, even when the stego-image is broken by an attacker, the secret image is protected by encryption. We implemented the 2-level image insertion and extraction algorithm by using C++ programming language. Experiment shows that the PSNR values of stego-images of ours exceed 30.00db which is the threshold of human recognition. The methodology of this study can be applied broadly to the information hiding and protection of the military secret images.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권12호
• /
• pp.5170-5188
• /
• 2015

This paper proposes a novel progressive secret image-hiding scheme based on the inpainting technique, the vector quantization technique (VQ) and the exploiting modification direction (EMD) technique. The proposed scheme first divides the secret image into non-overlapping blocks and categorizes the blocks into two groups: complex and smooth. The blocks in the complex group are compressed by VQ with PCA sorted codebook to obtain the VQ index table. Instead of embedding the original secret image, the proposed method progressively embeds the VQ index table into the cover images by using the EMD technique. After the receiver recovers the complex parts of the secret image by decoding the VQ index table from the shadow images, the smooth parts can be reconstructed by using the inpainting technique based on the content of the complex parts. The experimental results demonstrate that the proposed scheme not only has the advantage of progressive data hiding, which involves more shadow images joining to recover the secret image so as to produce a higher quality steganography image, but also can achieve high hiding capacity with acceptable recovered image quality.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권7호
• /
• pp.3116-3133
• /
• 2020

Based on the teleportation by quantum walk, a quantum secret sharing scheme with credible authentication is proposed. Using the Hash function and quantum local operation, combined with the two-step quantum walks circuit on the line, the identity authentication and the teleportation of the secret information in distribution phase are realized. Participants collaborate honestly to recover secret information based on particle measurement results, preventing untrusted agents and external attacks from obtaining useful information. Due to the application of quantum walk, the sender does not need to prepare the necessary entangled state in advance, simply encodes the information to be sent in the coin state, and applies the conditional shift operator between the coin space and the position space to produce the entangled state necessary for quantum teleportation. Security analysis shows that the protocol can effectively resist intercept/resend attacks, entanglement attacks, participant attacks, and impersonation attacks. In addition, the quantum walk circuit used has been implemented in many different physical systems and experiments, so this quantum secret sharing scheme may be achievable in the future.