In this paper we study a reversing train puzzle proposed by Sam Loyd near the turn of the century. We concern ourselves with a version of this puzzle described most recently by A. K. Dewdney in Scientific American. There is a train, locomotive and n cars, that must be entirely reversed using only a short spur line attached to the main track. The efficiency of a solution is determined by summing...

In this paper, we present a lower bound on secret distribution in star network. Examples of star communication network exist in various systems including sensor networks where there is one base station and several sensors that need to communicate with it. While the previous result had shown the possibility of performing secret distribution in a star network using 2 log n secrets, the lower boun...

10 In the ðt; nÞ multi-secret sharing scheme, there are n participants in the system. At 11 least t or more participants can easily pool their secrets shadows and reconstruct p 12 secrets at the same time. Chien et al. [IEICE Trans. Fundamentals E83-A (2000) 2762] 13 used (nþ p t þ 1) public values, ð2ðnþ pÞ tÞ ðnþ pÞ storages, and solved (nþ 14 p t) simultaneous equations to share p secrets. I...

In information-hiding, an adversary that tries to infer the secret information has a higher probability of success if it knows the distribution on the secrets. We show that if the system leaks probabilistically some information about the secrets, (that is, if there is a probabilistic correlation between the secrets and some observables) then the adversary can approximate such distribution by re...

Many peer-to-peer security protocols in mobile communications utilise shared secrets. Synchronous storage of shared secrets is imperative for the successful operation of security protocols, as asynchronous storage of shared secrets may lead to service unavailability. Hence, update mechanisms must not only guarantee the secrecy of shared secrets, but also their synchrony. This paper addresses sy...

This study examines who hears what secrets, comparing two similar secrets-one that is highly stigmatized and one that is less so. Using a unique survey representative of American adults and intake forms from a medical clinic, I document marked differences in who hears these secrets. People who are sympathetic to the stigmatizing secret are more likely to hear of it than those who may react nega...

One of the most interesting research topics in cryptography is nding schemes for an e cient fully-homomorphic encryption (FHE), preferably information-theoretically secure schemes, which are not based on unproven computational hardness assumptions. The greatest breakthrough in this eld was made by Gentry [11] in 2009, and since then there were some interesting developments, e.g., Boneh et al. [...

Passwords and PINs continue to remain the most widespread forms of user authentication, despite growing awareness of their security limitations. This is because short secrets are convenient, particularly for an increasingly mobile user population. Many users are interested in employing a variety of computing devices with different forms of connectivity and different software platforms. Such use...

The notion of a semi-commutativity set for word mappings was defined in [3] as an abstraction of a problem in cryptography. The notion is of special interest in case the mappings are morphisms. Then rather surprising constructions become possible. We investigate such constructions, paying special attention to exceptional values of inverse mappings. Some of our results bear a close relation to c...