This work develops a composable notion of security in a synchronous communication network to analyze cryptographic primitives and protocols in a reliable network with guaranteed delivery. In such a synchronous model the abort of protocols must be handled explicitly. It is shown that a version of global bit commitment which allows to identify parties that did not give proper input cannot be secu...

Oblivious transfer protocols (R-OT and OT1) are presented based on nonorthogonal states transmission, and the bit commitment protocols on the top of OT1 are constructed. Although these OT protocols are all unconditional secure, the bit commitment protocols based on OT protocols are not secure against attack similar to that presented by no-go theorem.

We present a new and very simple commitment scheme that does not depend on any assumptions about computational complexity the Sender and Receiver may both be computationally unbounded In stead the scheme utilizes a trusted initializer who participates only in an initial setup phase The scheme also utilizes private channels between each pair of parties The Sender is able to easily commit to a la...

Crisp Commitment schemes are very useful building blocks in the design of high-level cryptographic protocols. They are used as a mean of flipping fair coins between two players and others. In this paper an attempt has been made to give a generalized framework for Crisp Commitment schemes is called an Ordinary Crisp Commitment Scheme (OCCS). The Hiding and Binding properties of OCCS are well def...

In the present paper, we answer a question raised in the paper Constructions and Bounds for Unconditionally Secure Non-Interactive Commitment Schemes, by Blundo et al, 2002, showing that there is a close relation between unconditionally secure commitment schemes and unconditionally secure authentication schemes, and that an unconditionally secure commitment scheme can be built from such an auth...

This paper examines firms’ incentives to commit to a transparent behavior (that precludes bribery) in a competitive procedure modeled as an asymmetric information beauty contest managed by a corrupt agent. In his evaluation of firms’ offers for a public contract the agent has some discretion to favor a firm in exchange of a bribe. It is shown that a conditional commitment mechanism can eliminat...

The current research addresses the psychological benefits of superstitious rituals in top sport, examining the circumstances under which top-class sportspersons are especially committed to enacting rituals prior to a game (ritual commitment). Consistent with the hypotheses, findings revealed that ritual commitment is greater when (a) uncertainty is high rather than low; and (b) importance of th...

Mayers and independently Lo and Chau have shown that unconditionally secure quantum bit commitment is impossible. In this paper we show that under the assumption that the sender is not able to perform generalized measurements involving more than n qubits coherently (n-coherent measurements) then quantum bit commitment is possible. A commitment scheme is δ-binding if for each execution there is ...

In this work, we settle the relations among a variety of security notions related to non-malleability and CCA-security that have been proposed for commitment schemes in the literature. Interestingly, all our separations follow from two generic transformations. Given two appropriate security notions X and Y from the class of security notions we compare, these transformations take a commitment sc...

We consider the recent relativistic bit commitment protocol introduced by Lunghi et al. [Phys. Rev. Lett. 115, 030502 (2015)] and present a new security analysis against classical attacks. In particular, while the initial complexity of the protocol scales double exponentially with the commitment time, our analysis shows that the correct dependence is only linear. This has dramatic implications ...