The conventional way to speedup queries execution is by using indexes. Designing secure indexes for an encrypted database environment raises the question of how to construct the index so that no information about the database content is exposed. In this paper, the challenges raised when designing a secure index for an encrypted database are outlined; the attacker model is described; possible at...

In Shamir’s (t, n) secret sharing (SS) scheme, the secret s is divided into n shares by a dealer and is shared among n shareholders in such a way that any t or more than t shares can reconstruct this secret; but fewer than t shares cannot obtain any information about the secret s. In this paper, we will introduce the security problem that an adversary can obtain the secret when there are more t...

One of the most interesting research topics in cryptography is finding schemes for an efficient fully-homomorphic encryption (FHE), preferably information-theoretically secure schemes, which are not based on unproven computational hardness assumptions. The greatest breakthrough in the field of FHE schemes was made by Gentry [7] in 2009, and since then there were some interesting developments, e...

We consider the model of unconditionally secure (r-round, n-channel) message transmission schemes which was introduced by Dolev et al. [1]. In this model, there are n channels between a sender and a receiver, and an infinitely powerful adversary A may corrupt (observe and forge) the messages sent through t out of n channels. The sender wishes to send a secret s to the receiver in r-round withou...

This paper presents a recursive secret sharing technique that distributes k − 1 secrets of length b each into n shares such that each share is effectively of length n k−1 · b and any k pieces suffice for reconstructing all the k − 1 secrets. Since n k−1 is near the optimal factor of n/k, and can be chosen to be close to 1, the proposed technique is space efficient. Furthermore, each share is in...

While hardware resources, in the form of both transistors and full microprocessor cores, are now abundant, economic factors prevent specialized hardware mechanisms, required for secure processing, from being integrated into commodity parts. The Information Assurance community is caught between the need to exploit cheap, fast, commodity microprocessors and the need to ensure that critical securi...

For the application of large-scale mobile agents in a distributed environment, where a large number of computers are connected together to enable the large-scale sharing of data and computing resources, security and efficiency are of great concern. In this paper, we present secure route structures and corresponding protocols for mobile agents dispatched in binary to protect the dispatch route i...

A well-known fact in the theory of secret sharing schemes is that shares must be of length at least as the secret itself. However, the proof of this lower bound uses the notion of information theoretic secrecy. A natural (and very practical) question is whether one can do better for secret sharing if the notion of secrecy is computational, namely, against resource bounded adversaries. In this n...

The successful operation of NATO missions requires the effective and secure sharing of information among coalition partners and external organizations, while avoiding the disclosure of sensitive information to unauthorized users. To resolve the conflict between confidentiality and availability in a dynamic coalition and network environment while being able to dynamically respond to changes in p...

Mobility of users and information is an important feature of IT systems that must be considered during design of sensitive information protection mechanisms. This paper describes an architecture of MobInfoSec system for sharing documents with sensitive information using fine-grained access rules described by general access structures. However, the proper usage of general access structures requi...