Research Article
Vahid Meraji; Hadi Soleimany
Abstract
Numerous studies have been conducted to present new attacks using the time difference between the processor access to main memory and cache memory. Access-driven attacks are a series of cache-based attacks using fewer measurement samples to extract sensitive key values due to the ability of the attacker ...
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Numerous studies have been conducted to present new attacks using the time difference between the processor access to main memory and cache memory. Access-driven attacks are a series of cache-based attacks using fewer measurement samples to extract sensitive key values due to the ability of the attacker to evict or access cache lines compared to the other attacks based on this feature. In the access-driven attacks, the attacker frequently needs to evict or reload data from the cache memory before or after performing the targeted cryptosystem which requires the knowledge about the virtual or physical addresses. Knowledge of address offset for the corresponding data blocks in cryptographic libraries is a prerequisite for an adversary to reload or evict cache lines in Intel processors. Preventing the access of attackers to the address offsets can potentially be a countermeasure to mitigate access-driven attacks. In this paper, we demonstrate how to perform the Evict+Time attack on Intel x86 CPUs without any privilege of knowing address offsets.
Research Article
Salome James; Gowri Thumbur; P.Vasudeva Reddy
Abstract
In recent years, due to their potential applications, proxy blind signatures became an active research topic and are an extension of the basic proxy signature. A proxy blind signature scheme enables a proxy signer to produce a blind signature on behalf of an original signer. Such schemes are useful in ...
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In recent years, due to their potential applications, proxy blind signatures became an active research topic and are an extension of the basic proxy signature. A proxy blind signature scheme enables a proxy signer to produce a blind signature on behalf of an original signer. Such schemes are useful in many practical applications such as e-commerce, e-voting, e-tendering systems. Many proxy blind signature schemes have been proposed in the literature. In order to improve the efficiency and to adopt resource constrained devices, in this paper, we propose a pairing free ID-based proxy blind signature scheme with message recovery. The proposed scheme is proven secure against the random oracle model under the hardness assumption of the elliptic curve discrete logarithm problem. We compare our scheme with the other proxy blind signature schemes. The efficiency analysis shows that our scheme is more efficient in terms of computational and communicational point of view. Also due to the message recovery property, our scheme can be deployed easily in low band width devices.
Research Article
K. Nalini Sujantha Bel; I.Shatheesh Sam
Abstract
A novel feature extraction algorithm using Otsu’s Threshold (OT-features) on scrambled images and the Instantaneous Clustering (IC-CBIR) approach is proposed for Content-Based Image Retrieval in cloud computing. Images are stored in the cloud in an encrypted or scrambled form to preserve the privacy ...
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A novel feature extraction algorithm using Otsu’s Threshold (OT-features) on scrambled images and the Instantaneous Clustering (IC-CBIR) approach is proposed for Content-Based Image Retrieval in cloud computing. Images are stored in the cloud in an encrypted or scrambled form to preserve the privacy content of the images. The proposed method extracts the features from the scrambled images using the Otsu’s threshold. Initially, the Otsu’s threshold is estimated from the scrambled image and based on this threshold the image is divided into two classes in the first iteration. Again, the new threshold values are estimated from two classes. The difference between the new threshold and the previous threshold gives two features. This process is repeated for number of iteration to obtain the complete OT-features of the scrambled image. This paper also proposes an instantaneous clustering approach (IC-CBIR) where the image is moved into a cluster as soon as the image is uploaded by the image owner. Therefore while retrieving the images, the images near to a particular cluster are matched instead of matching with a complete set of image features in the dataset which reduces the search time. The performance of the proposed algorithm is being tested using four different types of the dataset such as Corel 10K, Misc, Oxford flower, and INRIA Holidays dataset. The experimental evaluation reveals that the proposed method outperforms better than the traditional CBIR algorithm on encrypted images in terms of precision, time of search and time of index construction.
Research Article
Mansoureh Labbafniya; Shahram Etemadi Borujeni; Roghaye Saeidi
Abstract
Nowadays the security of the design is so important because of the different available attacks to the system. the main aim of this paper is to improve the security of the circuit design implemented on FPGA device. Two approaches are proposed for this purpose. The first is to fill out empty space ...
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Nowadays the security of the design is so important because of the different available attacks to the system. the main aim of this paper is to improve the security of the circuit design implemented on FPGA device. Two approaches are proposed for this purpose. The first is to fill out empty space using flip-flops and LUTs so that there is no available space for inserting a hardware Trojan. We name this filling structure as Gate-chain. The second approach increases the security of the implemented design by identifying the low observable/controllable points of the main design and wiring them to the unused ports or the pre-designed Gate-chains. The proposed solutions not only prevent Trojan insertion but also increase the Trojan detection capabilities. Simulation results on Xilinx devices implementing different benchmarks show that the proposed method incurs dynamic power overhead just in test mode with less than one percent of delay overhead for critical path in normal mode.