Modification of images usually originates from channel noise, image processing operations or adversary's efforts. Image authentication mechanisms protect the authenticity of images by differentiating between the e...
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ISBN:
(纸本)9781467357517
Modification of images usually originates from channel noise, image processing operations or adversary's efforts. Image authentication mechanisms protect the authenticity of images by differentiating between the effects of malicious and acceptable alterations in the original image. This paper introduces a mechanism for approximate authentication and correction of images (AACI). The proposed scheme is constructed based on two approximate message authentication code (AMAC) frameworks which use standard cryptographic primitives and error-correcting codes as their building blocks. The AACI tolerates acceptable modifications which are not effective in the image recovery process. The malicious modifications can be detected and the damaged parts can be restored by an AACI mechanism up to a certain limit. In this work, the specification of the AACI mechanism is given, proposed settings, performance and security analysis of the AACI are discussed and simulation results are presented.
Hamming code is a parity code, the information bits and test bits must be mixed arrangement at a fixed location to check for errors s and correct the wrong. Based on the design principle of Hamming codes, this paper g...
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Hamming code is a parity code, the information bits and test bits must be mixed arrangement at a fixed location to check for errors s and correct the wrong. Based on the design principle of Hamming codes, this paper gives a improved method, proposed to arrangements the test bits in the last digit of code word, so that extract the information bit more convenient, and hardware implementation will be easier.
Low-density parity-check (LDPC) codes constructed by a sparse parity-check matrix are of very fast encoding and decoding algorithms. Another kind of codes, which improved the well-known Gilbert-Varshamov bound, a...
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Low-density parity-check (LDPC) codes constructed by a sparse parity-check matrix are of very fast encoding and decoding algorithms. Another kind of codes, which improved the well-known Gilbert-Varshamov bound, are algebraic geometry codes (Goppa geometry codes) from algebraic curves over finite fields. In the note, we analyze their characteristic of the two class of codes and show that the algebraic geometric codes are seldom LDPC codes.
Fast decoder of BCH code (31, 16, 7) which based on matrix algorithm of syndromes computation and parallel data processing was developed. Functional blocks of developed device based on block-based design were describe...
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ISBN:
(纸本)9781467383844
Fast decoder of BCH code (31, 16, 7) which based on matrix algorithm of syndromes computation and parallel data processing was developed. Functional blocks of developed device based on block-based design were described. Device testing with coding and decoding modes and 50 MHz frequency was conducted.
The structure of the BCH code decoder based on the cyclic decoding method with classic and fast dividing polynomials algorithms was presented. A comparison of algorithms was provided, the conclusion about hardware cos...
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The structure of the BCH code decoder based on the cyclic decoding method with classic and fast dividing polynomials algorithms was presented. A comparison of algorithms was provided, the conclusion about hardware costs for algorithms implementing and about high-speed advantage over the classical algorithm was done.
As the power distribution grid moves towards actualizing the concept of a smart grid, the dependence of reliable and secure grid operation on the communication architecture and data is increasing rapidly, along with t...
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ISBN:
(纸本)9781509041695
As the power distribution grid moves towards actualizing the concept of a smart grid, the dependence of reliable and secure grid operation on the communication architecture and data is increasing rapidly, along with the possible cyber-attack surface. In this paper first an agreement algorithm for a distribution substation with radial topology is presented that leverages the communication capabilities under the IEC61850 standard, along with basic power system concepts such as Kirchhoff's laws, to detect and locate a data injection attack in the communication system, a relay misconfiguration or a sensor failure that can cause an incorrect response to actual or apparent fault currents. Then a setup for a collaborative mechanism using the algorithm to detect and deter the impacts of such a data injection attack under different grid operating scenarios is introduced. The results of the demonstration of this setup, presented here, show that the proposed collaborative mechanism is consistently able to detect and deter the impacts of data injection and misconfiguration attacks as well as sensor failures in the IEC61850-based smart substation.
A Viterbi code is a type of the well-known errorcorrectingcode (ECC), which provides a robust error control methodology for wireless communication systems. It can efficiently reduce the bit error rate of the receive...
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Because of continuous scaling down to small dimensions, DRAM has become a main memory with high capacity and density. Because denser memories are likely to contain more errors, DRAM employs repair schemes that replace...
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ISBN:
(纸本)9781467384551
Because of continuous scaling down to small dimensions, DRAM has become a main memory with high capacity and density. Because denser memories are likely to contain more errors, DRAM employs repair schemes that replace errors with good cells for yield enhancement of a memory. The conventional repair scheme covers only manufacturing-level errors. As DRAM wears out while operating in the field, to enhance the lifetime of a memory, we need to incorporate a post-package repair scheme into a memory system for repairing aging errors. In this paper, we propose a methodology that repairs aging errors in a memory during field operations. Using the memory yield and lifetime simulator, we evaluate the proposed repair method. Employing a 2GB DDR3 ECC-DIMM as a case study, we demonstrate that our post-package repair scheme improves the yield and the lifetime of a memory.
In digital VCRs for home use, the video signal for each field is recorded on multiple tracks. Thus, it is difficult to reproduce the video signal smoothly in high-speed trick playback, where the signal is restored by ...
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