Strong Continuous Non-malleable Encoding Schemes with Tamper-Detection

A non-malleable encoding scheme is a keyless encoding scheme which is resilient to tampering attacks. Such a scheme is said to be continuously secure if the scheme is resilient to attacks containing more than one tampering procedure. Also, such a scheme is said to have tamper-detection property if any kind of tampering attack is detected. In [S. Faust, et al., Continuous nonmalleable codes, TCC Proc., LNCS Vol. 8349, 2014.] a general continuous non-malleable encoding scheme based on NIZK is introduced which is secure in a strong model for which the adversary receives a no-tamper as a response to its tampering query if the decoding of the tampered codeword is identical to the original message. In this article we introduce a new strongly secure continuous non-malleable encoding scheme with tamper-detection property whose security is based on the existence of secure MAC’s. Moreover, we introduce and justify the importance of an intermediate security model called semi-strong continuous non-malleability, while we provide a secure semi-strong continuous non-malleable encoding scheme whose security is based on the existence of CCA-secure public-key encryption. Considering the area of applications of encoding schemes in tamper-proof devices, it is instructive to note that our proposed schemes can be used to implement an algorithmic tamperdetection level as well as maintaining the security conditions

FMNV Continuous Non-malleable Encoding Scheme is More Efficient Than Believed

Non-malleable codes are kind of encoding schemes which are resilient to tampering attacks. The main idea behind the non-malleable coding is that the adversary can\u27t be able to obtain any valuable information about the message. Non-malleable codes are used in tamper resilient cryptography and protecting memory against tampering attacks. Several kinds of definitions for the non-malleability exist in the literature. The Continuous non-malleability is aiming to protect messages against the adversary who issues polynomially many tampering queries. The first continuous non-malleable encoding scheme has been proposed by Faust et el. (FMNV) in 2014. In this paper, we propose a new method for proving continuous non-malleability of FMNV scheme. This new proof leads to an improved and more efficient scheme than previous one. The new proof shows we can have the continuous non-malleability with the same security by using a leakage resilient storage scheme with about (k+1)(log(q)-2) bits fewer leakage bound (where k is the output size of the collision resistant hash function and q is the maximum number of tampering queries)

A 12-bit track and hold amplifier for giga-sample applications

The paper presents a track-and-hold amplifier (THA), based on the switched emitter follower topology, suitable for emerging receivers architectures and data acquisition systems. The THA exploits four concurrent techniques, all described in the paper, which allow to reduce the hold-mode feedthrough; to attenuate the differential droop rate; to improve the linearity of the input buffer; and to optimize the third order harmonic distortion for RF sampling operation. The effectiveness of this novel approach is demonstrated using a low cost 0.35 μm SiGe technology. The THA core draws about 145 mA from 3.5 V supply. The THA provides a spurious-free dynamic range (SFDR) better than 72 dB when it is used for sampling an incoming signal of 0.9 Vpp centered around 925 MHz at a sampling rate of 0.5 GS/s. The THA allows a max sampling frequency equal to 6 GS/s and a max input frequency equal to 2.5 GHz and provides a SFDR better than 50 dB in all the available working conditions

Managing Incompatible Impacts of Organizational Values on Knowledge Sharing

At any given time the two rival organizational values cooperation and competition coexist in any team and/or organization in different intensities and mix, depending on both internal factors (e.g., culture, task dimensions of accuracy and speed) and external factors (e.g., market and competitive forces). However, determining that desirable intensity and mix of these two values seems to be a challenging task in the current literature and no explicit method currently exists for measuring factors that may lead to determination of such desirable mix. Considering the crucial impacts of these values on organizational behaviours, this in turn may result in loss of efficiency and productivity in organizations. In this study a systematic review of current literatures in the areas of knowledge management, social psychology, organizational studies and Computer-Supported Cooperative Systems (CSCW) studies, is used to uncover a research theme for analysing the impacts of the two rival organizational values competition and cooperation on knowledge sharing behaviours through promotive interaction between individuals. Supporting the IT-culture conflict theory, this study is considered as a research theme which investigates the impact of culture on IT application and use. More specifically, by combining the goal interdependency theory of conflict, social learning theory, the internal organizational forces of competition and cooperation and the awareness net analysis, the present study deeply investigate the term tension between cooperative and competitive values and their impact on organizational behaviours. It then introduces factors that can assist in finding an optimal mix of the cooperative and competitive values in organizations at any given time. The present study also relates the above optimal mix/tension with the organization’s reward structure, the task dimensions of ‘speed’ and ‘accuracy’, group characteristics and organizational climate in order to draw inferences for attaining an optimal level of process awareness for individuals while performing their tasks within an organization