Because of the speed limitation of the conventional bit-selection strategy in the exi- sting weighted bit flipping algorithms, a high- speed Low-Density Parity-Check （LDPC） dec- oder cannot be realised. To solve thi...Because of the speed limitation of the conventional bit-selection strategy in the exi- sting weighted bit flipping algorithms, a high- speed Low-Density Parity-Check （LDPC） dec- oder cannot be realised. To solve this problem, we propose a fast weighted bit flipping algo- rithm. Specifically, based on the identically dis- tributed error bits, a parallel bit-selection met- hod is proposed to reduce the selection delay of the flipped bits. The delay analysis demon- strates that, the decoding speed of LDPC codes can be significantly improved by the proposed algorithm. Furthermore, simulation results ver- ify the validity of the proposed algorithm.展开更多
Side-channel attacks have recently progressed into software-induced attacks.In particular,a rowhammer attack,which exploits the characteristics of dynamic random access memory(DRAM),can quickly and continuously access...Side-channel attacks have recently progressed into software-induced attacks.In particular,a rowhammer attack,which exploits the characteristics of dynamic random access memory(DRAM),can quickly and continuously access the cells as the cell density of DRAM increases,thereby generating a disturbance error affecting the neighboring cells,resulting in bit flips.Although a rowhammer attack is a highly sophisticated attack in which disturbance errors are deliberately generated into data bits,it has been reported that it can be exploited on various platforms such as mobile devices,web browsers,and virtual machines.Furthermore,there have been studies on bypassing the defense measures of DRAM manufacturers and the like to respond to rowhammer attacks.A rowhammer attack can control user access and compromise the integrity of sensitive data with attacks such as a privilege escalation and an alteration of the encryption keys.In an attempt to mitigate a rowhammer attack,various hardware-and software-based mitigation techniques are being studied,but there are limitations in that the research methods do not detect the rowhammer attack in advance,causing overhead or degradation of the system performance.Therefore,in this study,a rowhammer attack detection technique is proposed by extracting common features of rowhammer attack files through a static analysis of rowhammer attack codes.展开更多
Polar codes are considered as one of the most competitive channel coding schemes for the future wireless communication system.To improve the performance of polar codes with short code-length for control channels,a sph...Polar codes are considered as one of the most competitive channel coding schemes for the future wireless communication system.To improve the performance of polar codes with short code-length for control channels,a sphere decoding algorithm based on received value flipping is proposed in this paper.When a codeword fails the cyclic redundancy check,the algorithm flips the received value with low reliability and forms a new received sequence.Then,this new sequence is sent to the decoder for another decoding attempt.In addition,we also compare the performance of different flipping sets and evaluate the influence of the associated flipping set sizes.Simulation results show that,the proposed algorithm can achieve performance improvement over additive white Gaussian noise channel with acceptable complexity.For the(64,16)polar code,the proposed algorithm can achieve about 0.23 dB 10-3performance gain at frame error rate=,compared to the conventional sphere decoding algorithm.Finally,we also verify the applicability of the proposed algorithm over Rayleigh fading channel and observe similar results.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant No.61072069the Fundamental Research Funds for the Central Universities under Grant No.72001859+1 种基金the Important National Science and Technology Specific Projects under Grant No.2011ZX03003-001-04the One Church,One Family,One Purpose Project(111 Project)under Grant No.B08038
文摘Because of the speed limitation of the conventional bit-selection strategy in the exi- sting weighted bit flipping algorithms, a high- speed Low-Density Parity-Check （LDPC） dec- oder cannot be realised. To solve this problem, we propose a fast weighted bit flipping algo- rithm. Specifically, based on the identically dis- tributed error bits, a parallel bit-selection met- hod is proposed to reduce the selection delay of the flipped bits. The delay analysis demon- strates that, the decoding speed of LDPC codes can be significantly improved by the proposed algorithm. Furthermore, simulation results ver- ify the validity of the proposed algorithm.
基金supported by a National Research Foundation of Korea(NRF)Grant funded by the Korean government(MSIT)(No.NRF-2017R1E1A1A01075110).
文摘Side-channel attacks have recently progressed into software-induced attacks.In particular,a rowhammer attack,which exploits the characteristics of dynamic random access memory(DRAM),can quickly and continuously access the cells as the cell density of DRAM increases,thereby generating a disturbance error affecting the neighboring cells,resulting in bit flips.Although a rowhammer attack is a highly sophisticated attack in which disturbance errors are deliberately generated into data bits,it has been reported that it can be exploited on various platforms such as mobile devices,web browsers,and virtual machines.Furthermore,there have been studies on bypassing the defense measures of DRAM manufacturers and the like to respond to rowhammer attacks.A rowhammer attack can control user access and compromise the integrity of sensitive data with attacks such as a privilege escalation and an alteration of the encryption keys.In an attempt to mitigate a rowhammer attack,various hardware-and software-based mitigation techniques are being studied,but there are limitations in that the research methods do not detect the rowhammer attack in advance,causing overhead or degradation of the system performance.Therefore,in this study,a rowhammer attack detection technique is proposed by extracting common features of rowhammer attack files through a static analysis of rowhammer attack codes.
基金supported by the National Natural Science Foundation of China(Nos.61961004,62261003,and 62361003)the Key Research and Development Program of Guangxi(No.GuiKeAB22080048)the Counterpart Aid Project for Discipline Construction from Guangxi University(No.2023N04).
文摘Polar codes are considered as one of the most competitive channel coding schemes for the future wireless communication system.To improve the performance of polar codes with short code-length for control channels,a sphere decoding algorithm based on received value flipping is proposed in this paper.When a codeword fails the cyclic redundancy check,the algorithm flips the received value with low reliability and forms a new received sequence.Then,this new sequence is sent to the decoder for another decoding attempt.In addition,we also compare the performance of different flipping sets and evaluate the influence of the associated flipping set sizes.Simulation results show that,the proposed algorithm can achieve performance improvement over additive white Gaussian noise channel with acceptable complexity.For the(64,16)polar code,the proposed algorithm can achieve about 0.23 dB 10-3performance gain at frame error rate=,compared to the conventional sphere decoding algorithm.Finally,we also verify the applicability of the proposed algorithm over Rayleigh fading channel and observe similar results.
