A generalization of the Mignotte's scheme over Euclidean domains and applications to secret image sharing

Secret sharing scheme is an efficient method to hide secret key or secret image by partitioning it into parts such that some predetermined subsets of partitions can recover the secret but remaining subsets cannot. In 1979, the pioneer construction on this area was given by Shamir and Blakley independently. After these initial studies, Asmuth-Bloom and Mignotte have proposed a different $(k,n)$ threshold modular secret sharing scheme by using the Chinese remainder theorem. In this study, we explore the generalization of Mignotte's scheme to Euclidean domains for which we obtain some promising results. Next, we propose new algorithms to construct threshold secret image sharing schemes by using Mignotte's scheme over polynomial rings. Finally, we compare our proposed scheme to the existing ones and we show that this new method is more efficient and it has higher security

Sequential Circuit Design for Embedded Cryptographic Applications Resilient to Adversarial Faults

In the relatively young field of fault-tolerant cryptography, the main research effort has focused exclusively on the protection of the data path of cryptographic circuits. To date, however, we have not found any work that aims at protecting the control logic of these circuits against fault attacks, which thus remains the proverbial Achilles’ heel. Motivated by a hypothetical yet realistic fault analysis attack that, in principle, could be mounted against any modular exponentiation engine, even one with appropriate data path protection, we set out to close this remaining gap. In this paper, we present guidelines for the design of multifault-resilient sequential control logic based on standard Error-Detecting Codes (EDCs) with large minimum distance. We introduce a metric that measures the effectiveness of the error detection technique in terms of the effort the attacker has to make in relation to the area overhead spent in implementing the EDC. Our comparison shows that the proposed EDC-based technique provides superior performance when compared against regular N-modular redundancy techniques. Furthermore, our technique scales well and does not affect the critical path delay

Mental Card Gaming Protocols Supportive Of Gameplay Versatility, Robustness And Efficiency

Pennainan kad mental merupakan protokol kriptografi yang membolehkan pennainan yang ~ disahkan adil di kalangan parti-parti jauh yang penyangsi dan berpotensi menipu. Pennainan kad ini setidak-tidaknya patut menyokong-tanpa memperkenal~an parti ketiga yang dipercayai (TTP)--rahsia kad, pengesanan penipuan dan keselamatan bersyarat ke atas pakatan pemain. Tambahan kepada keperJuan asas ini, kami meninjau isu-isu pennainan kad mental yang berkaitan dengan fungsian permainan, keteguhan operasional dan kecekapan implementasi. Pengkajian kami diberangsang oleh potensi pennainan berasaskan komputer dan rangkaian yang melewati batas kemampuan kad fizikal, terutamanya pembongkaran maklumat terperinci kad (seperti warna, darjat, simbol atau kebangsawanan) sambil merahsiakan nilai keseluruhan kad tersebut. ~. Mental card games are cryptographic protocols which permit verifiably fair gameplay among a l< ~. priori distrustful and potentially untrustworthy remote parties and should minimally providewithout the introduction of a trusted third party (TTP)---for card confidentiality, fraud detection and conditional security against collusion. In addition to these basic requirements, we explore into gameplay functionality, operational robustness and implementation efficiency issues of mental card gaming. Our research is incited by the potential of computer-based and networkmediated gameplay beyond the capability of physical cards, particularly fine-grained information disclosure (such as colour, rank, symbol or courtliness) with preservation of card secrecy. On the other hand, being network connected renders the protocol susceptible to (accidental or intentional) disconnection attack, as well as other malicious behaviours

Privacy preserving distributed optimization using homomorphic encryption

This paper studies how a system operator and a set of agents securely execute a distributed projected gradient-based algorithm. In particular, each participant holds a set of problem coefficients and/or states whose values are private to the data owner. The concerned problem raises two questions: how to securely compute given functions; and which functions should be computed in the first place. For the first question, by using the techniques of homomorphic encryption, we propose novel algorithms which can achieve secure multiparty computation with perfect correctness. For the second question, we identify a class of functions which can be securely computed. The correctness and computational efficiency of the proposed algorithms are verified by two case studies of power systems, one on a demand response problem and the other on an optimal power flow problem.Comment: 24 pages, 5 figures, journa

CapablePtrs: Securely Compiling Partial Programs using the Pointers-as-Capabilities Principle

Capability machines such as CHERI provide memory capabilities that can be used by compilers to provide security benefits for compiled code (e.g., memory safety). The C to CHERI compiler, for example, achieves memory safety by following a principle called "pointers as capabilities" (PAC). Informally, PAC says that a compiler should represent a source language pointer as a machine code capability. But the security properties of PAC compilers are not yet well understood. We show that memory safety is only one aspect, and that PAC compilers can provide significant additional security guarantees for partial programs: the compiler can provide guarantees for a compilation unit, even if that compilation unit is later linked to attacker-controlled machine code. This paper is the first to study the security of PAC compilers for partial programs formally. We prove for a model of such a compiler that it is fully abstract. The proof uses a novel proof technique (dubbed TrICL, read trickle), which is of broad interest because it reuses and extends the compiler correctness relation in a natural way, as we demonstrate. We implement our compiler on top of the CHERI platform and show that it can compile legacy C code with minimal code changes. We provide performance benchmarks that show how performance overhead is proportional to the number of cross-compilation-unit function calls

Efficient non-malleable commitment schemes

We present efficient non-malleable commitment schemes based on standard assumptions such as RSA and Discrete-Log, and under the condition that the network provides publicly available RSA or Discrete-Log parameters generated by a trusted party. Our protocols require only three rounds and a few modular exponentiations. We also discuss the difference between the notion of non-malleable commitment schemes used by Dolev, Dwork and Naor [DDN00] and the one given by Di Crescenzo, Ishai and Ostrovsky [DIO98]