Improvements of image sharing with steganography and authentication

General Secret Sharing Based on the Chinese Remainder Theorem.

General Secret Sharing Based on the Chinese Remainder Theorem with Applications in E-Voting

Preface A secret sharing scheme starts with a secret and then derives from it certain shares (or shadows) which are distributed to users. The secret may be recovered only by certain predetermined groups which belong to the access structure. Secret sharing schemes have been independently introduced by Blakley [12] and Shamir [134] as a solution for safeguarding cryptographic keys. Secret sharing schemes can be used for any situation in which the access to an important resource has to be restricted. We mention here the case of opening bank vaults or launching a nuclear missile. In the first secret sharing schemes only the number of the participants in the reconstruction phase was important for recovering the secret. Such schemes have been referred to as threshold secret sharing schemes. There are secret sharing schemes that deal with more complex access structures than the threshold ones. We mention here the weighted threshold secret sharing schemes in which a positive weight is associated to each user and the secret can be reconstructed if and only if the sum of the weights of the participants is greater than or equal to a fixed threshold, the hierarchical (or multilevel) secret sharing schemes in which the set of users is partitioned into some levels and the secret can be recovered if and only if there is an initialization level such that the number of the participants from this level or higher levels is greater than or equal to the initialization level threshold, the compartmented secret sharing schemes in which the set of users is partitioned into compartments and the secret can be recovered if and only if the number of participants from any compartment is greater than or equal to a compartment threshold and the total number of participants is greater than or equal to a global threshold. Ito, Saito, and Nishizeki [90], Benaloh and Leichter [9] have proposed constructions for realizing any monotone (i.e., if a group belongs to the access structure, so does a larger group) access iii iv structure. The schemes in which the unauthorized groups gain no information about the secret are referred to as perfect. Karnin, Greene, and Hellman [97] have proved, using the concept of entropy, that in any perfect threshold secret sharing scheme the shares must be at least as long as the secret and, later on, Capocelli, De Santis, Gargano, and Vaccaro [27] have extended this result to the …

Secret Sharing Schemes with Applications in Security Protocols.

. A reversible watermarking scheme for relational databases is proposed in this paper to achieve lossless and exact authentication of relational databases via expansion on data error histogram. This reversi-ble watermarking scheme possesses the ability of perfect restoration of the original attribute data from the un-tampered watermarked relational databases, thus guaranteeing a “clear and exact” tampered-or-not authenti-cation without worry about causing any permanent distortion to the database. In this scenario, only the secret key owner possesses the capability to exactly restore the database’s original state. Simulations demonstrate the scheme’s security and feasibility for low-correlated data in typical databases. Keywords: reversible watermark, digital watermarking, relational databases 1 Introduction Security is of increasing concern with databases for database’s high added values and extensive installation in modern information systems. In addition to encryption, watermarking techniques is practically proven as another possible solution to enhance databases’ content security especially for copyright protection [1-6] and data tam-pering detection [7]. Unlike encryption or hash description, typical watermarking techniques modify original data as a modulation of the watermark information, and inevitably cause permanent distortion to the original data, and therefore cannot meet the integrity requirement of the data in some applications. This underlying defect can be relieved by reversible watermarking techniques [8-22] by their reversibility in both robust watermarking [8,9] and fragile watermarking [10-18]. The direct beneficiary from this reversibility is those applications requiring zero permanent distortions such as medical imaging, military imaging, forensics of documents and art work au-thentication. On the other hand, the perfect restoring ability realizes watermarking based lossless authentication which accounts for the major part of earlier algorithms [8-11]. In recent years, researches on reversible water-marking center on increasing embedding capacity to meet requirements of large volume data embedding [12-18]. In the meanwhile, its applications reach to non-raster image fields [20-22]. However so far, almost all the re-versible watermarking schemes exploit high correlation among neighboring data samples, and therefore face difficulty in the application of relational databases which usually contains only low-correlated, or even in the extreme case, completely random generated data. Some schemes were proposed [1-6] to watermark relational databases for copyright protection, which are based on the facts that the relational data have enough redundancy and can tolerate some unnoticeable degrada-tion in data precision caused by watermark embedding. The targets of the papers [1-6] are to verify the copyright of the relational data and the ownership of the owner, and the fragile watermarking scheme algorithm proposed in [7] is to detect and localize the tampered area of relational data, which however, inevitably introduces permanent distortion to the cover data.

Reversible Watermarking for Relational Database Authentication

We prove that the verifiable secret sharing scheme of C. Asmuth and J. Bloom (see IEEE Trans. Inform. Theory, vol.IT-29.547, p.208-10, 1983) is not realizable although their basic modular secret sharing scheme is efficient and perfect. An efficient non-interactive modular verifiable secret sharing scheme is proposed, based on their basic scheme. The verification needs about (2|q|n+(n-1))r multiplications. The secret recovery takes O(r) operations while A. Shamir's scheme (1979) takes O(r log/sup 2/ r) operations. It is also shown that the scheme is a perfect secret sharing scheme.

http://ieeexplore.ieee.org/iel5/9992/32104/01493367.pdf

A non-interactive modular verifiable secret sharing scheme

As one of the most important procedure in quantum key distribution system, the error reconciliation algorithm has drew many attentions. However, studies on the error reconciliation algorithm mainly focuses on the reconciliation efficiency. Since the ultimate goal of study on the error reconciliation is to find the most suitable algorithm for a quantum key distribution system and maximize the throughput rate of the whole system, the indicator of reconciliation efficiency is not full-scale enough to evaluate an error reconciliation algorithm. In this paper we propose a new evaluation scheme, including four direct indicators and one composite indicator to solve the problem. Following the new scheme, seven representative error reconciliation algorithms are simulated and compared thoroughly, i.e. BBBSS, the original Cascade and two improved Cascade algorithms, Winnow, and two LDPC based algorithms. Our works are very beneficial to the evaluation, comparison, selection and optimization of error reconciliation algorithms for a practical quantum key distribution system.

Study on error reconciliation in quantum key distribution

To protect the copyright of relational database is an important task. It's a great challenge as well as has a practical application. In this paper, a novel method of watermarking is presented to protect relational databases copyright. The watermark embedding and extraction algorithms are specified, the results of the corresponding watermark experiments and the attack experiments verify that the proposed method is correct, feasible and robust.

Niu Xia-mu

Papers

A non-interactive modular verifiable secret sharing scheme

Study on error reconciliation in quantum key distribution

A novel method of watermarking relational databases using character string