Efficient, XOR-Based, Ideal (t,n)− threshold Schemes

We propose a new, lightweight (t; n) threshold secret shar- ing scheme that can be implemented using only XOR operations. Our scheme is based on an idea extracted from a patent application by Hewlett Packard that utilises error correction codes. Our scheme im- proves on the patent by requiring fewer randomly generated bits and by reducing the size of shares given to each player, thereby making the scheme ideal. We provide a security proof and e ciency analysis. We compare our scheme to existing schemes in the literature and show that our scheme is more e cient than other schemes, especially when t is large

Secure RAID Schemes for Distributed Storage

We propose secure RAID, i.e., low-complexity schemes to store information in a distributed manner that is resilient to node failures and resistant to node eavesdropping. We generalize the concept of systematic encoding to secure RAID and show that systematic schemes have significant advantages in the efficiencies of encoding, decoding and random access. For the practical high rate regime, we construct three XOR-based systematic secure RAID schemes with optimal or almost optimal encoding and decoding complexities, from the EVENODD codes and B codes, which are array codes widely used in the RAID architecture. The schemes can tolerate up to two node failures and two eavesdropping nodes. For more general parameters we construct systematic secure RAID schemes from Reed-Solomon codes, and show that they are significantly more efficient than Shamir’s secret sharing scheme. Our results suggest that building “keyless”, information-theoretic security into the RAID architecture is practical

How to Work with Honest but Curious Judges? (Preliminary Report)

The three-judges protocol, recently advocated by Mclver and Morgan as an example of stepwise refinement of security protocols, studies how to securely compute the majority function to reach a final verdict without revealing each individual judge's decision. We extend their protocol in two different ways for an arbitrary number of 2n+1 judges. The first generalisation is inherently centralised, in the sense that it requires a judge as a leader who collects information from others, computes the majority function, and announces the final result. A different approach can be obtained by slightly modifying the well-known dining cryptographers protocol, however it reveals the number of votes rather than the final verdict. We define a notion of conditional anonymity in order to analyse these two solutions. Both of them have been checked in the model checker MCMAS

Threshold Implementations of the Present Cipher

The process of securing data has always been a challenge since it is related to the safety of people and society. Nowadays, there are many cryptographic algorithms developed to solve security problems. However, some applications have constraints which make it difficult to achieve high levels of security. Light weight cryptography aims to address this issue while trying to maintain low costs. Side-channel attacks have changed the way of cryptography significantly. In this kind of attacks, the attacker has physical access to the crypto-system and can extract the sensitive data by monitoring and measuring the side-channels such as power consumption, electromagnetic emanation, timing information, sound, etc. These attacks are based on the relationship between side-channels and secret data. Therefore, there need to be countermeasures to eliminate or reduce side channel leaks or to break the relationship between side-channels and secret data to protect the crypto systems against side-channel attacks. In this work, we explore the practicality of Threshold Implementation (TI) with only two shares for a smaller design that needs less randomness but is still leakage resistant. We demonstrate the first two-share Threshold Implementations of light-weight block cipher Present. Based on implementation results, two-share TI has a lower area overhead and better throughput when compared with a first-order resistant three-share scheme. Leakage analysis of the developed implementations reveals that two-share TI can retain perfect first-order resistance. However, the analysis also exposes a strong second-order leakage

A New Approach To Public-Key Cryptosystem Based On Mandelbrot And Julia Fractal Sets.

Kajian ini mencadangkan primitif baru kekunci-awam berasaskan kepada set Fraktal Mandelbrot dan Julia. Penciptaan kekunci-awam primitif berasas Fraktal boleh dilakukan kerana perkaitan yang kuat di antara set Fraktal Mandelbrot dan set Fraktal Julia. This study proposes new public-key primitives based on Mandelbrot and Julia Fractal sets. The creation of the Fractal based public-key primitives is possible because of the strong connection between the Mandelbrot and Julia Fractal sets

The Potential for Machine Learning Analysis over Encrypted Data in Cloud-based Clinical Decision Support - Background and Review

This paper appeared at the 8th Australasian Workshop on Health Informatics and Knowledge Management (HIKM 2015), Sydney, Australia, January 2015. Conferences in Research and Practice in Information Technology (CRPIT), Vol. 164, Anthony Maeder and Jim Warren, Ed. Reproduction for academic, not-for profit purposes permitted provided this text is includedIn an effort to reduce the risk of sensitive data exposure in untrusted networks such as the public cloud, increasing attention has recently been given to encryption schemes that allow specific computations to occur on encrypted data, without the need for decryption. This relies on the fact that some encryption algorithms display the property of homomorphism, which allows them to manipulate data in a meaningful way while still in encrypted form. Such a framework would find particular relevance in Clinical Decision Support (CDS) applications deployed in the public cloud. CDS applications have an important computational and analytical role over confidential healthcare information with the aim of supporting decision-making in clinical practice. This review paper examines the history and current status of homomoprhic encryption and its potential for preserving the privacy of patient data underpinning cloud-based CDS applications