Reconfigurable computing has grown to become an important and large field of research, it offers advantages over traditional hardware and software implementations of computational algorithms. The Advanced Encryption S...Reconfigurable computing has grown to become an important and large field of research, it offers advantages over traditional hardware and software implementations of computational algorithms. The Advanced Encryption Standard （AES） algorithm is widely applied in government department and commerce. This paper analyzed the AES algorithms with different cipher keys, adopted a novel key scheduler that generated the round key real-time, proposed a dynamically reconfigurable encryption system which supported the AES algorithm with different cipher keys, and designed the architecture of the reconfigurable system. The dynamically reconfigurable AES system had been realized on FPGA. The result proves that the reconfigurable AES system is flexible, lower cost and high security level.展开更多
A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential pro...A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential probability （LDP）. Moreover, we present a new method for upper bounding the maximum linear-differential probability （MLDP） for 2 rounds of substitution permutation network （SPN） cipher structure. When our result applies to 2-round advanced encryption standard（AES）, It is shown that the upper bound of MLDP is up to 1.68×2^-19, which extends the known results for the 2-round SPN. Furthermore, when using a recursive technique, we obtain that the MLDP for 4 rounds of AES is bounded by 2^-73.展开更多
The specimens were implanted with aluminum ions with fluence ranging from 1× 10^16 to 1× 10^17 ions/cm^2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by me...The specimens were implanted with aluminum ions with fluence ranging from 1× 10^16 to 1× 10^17 ions/cm^2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by metal vapor vacuum arc source （MEVVA） at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）, respectively. Transmission electron microscopy （TEM） was used to examine the microstructure of the aluminum-implanted samples. Glancing angle X-ray diffraction （GAXRD） was employed to examine the phase transformation due to the aluminum ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-2 in a 1 M H2SO4 solution. It is found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-2 implanted with aluminum ions. Finally, the mechanism of the corrosion behavior of aluminum- implanted zircaloy-2 was discussed.展开更多
In order to study the effect of copper ion implantation on the aqueous corrosion behavior of ZIRLO alloy, specimens were implanted with copper ions with fluences ranging from 1×10^16 to 1×10^ ions/cm^2, usin...In order to study the effect of copper ion implantation on the aqueous corrosion behavior of ZIRLO alloy, specimens were implanted with copper ions with fluences ranging from 1×10^16 to 1×10^ ions/cm^2, using a metal vapor vacuum arc source （MEVVA） at an extraction voltage of 40 kV, The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）, respectively. Glancing angle X-ray diffraction （GAXRD） was employed to examine the phase transformation due to the copper ion implantation. The potcntiodynamic polarization technique was used to evaluate the aqueous corrosion resistance of implanted ZIRLO alloy in a 1 mol/L H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of ZIRLO alloy implanted with copper ions when the fluence is 5×10^16 ions/cm^2. When the fluence is 1×10^16 or 1×10^17 ions/cm^2, the corrosion resistance of implanted sanaples was bad. Finally, the mechanism of the corrosion behavior of copper-implanted ZIRLO alloy was discussed.展开更多
Application of embedded systems is faced with multiple threats against security. To solve this problem, this article proposes a new program memory encryption mechanism （PEM） to enhance the security of embedded proce...Application of embedded systems is faced with multiple threats against security. To solve this problem, this article proposes a new program memory encryption mechanism （PEM） to enhance the security of embedded processor. The new mechanism encrypts all the programs via a secure cache structure. It not only caches the instructions read from the off-chip memory, but also stores the pad values used to encrypt the plaintext. It effectively accelerates encryption and reduces the performance overhead. Besides the encryption, PEM also monitors the program modifications and reset behaviors to reduce the risk of vicious tamper. The experiment indicates that PEM has an average of 2.3 % performance improvement and results in a 25.71% power reduction in the write-back stage. The new scheme offers a good balance between performance and security. It is fully practicable for embedded processor.展开更多
The chemical composition and semi-conductive properties of passive film on nickel- based alloy （G3 alloy） in bicarbonate/carbonate buffer solution were investigated by Auger electron spectroscopy （AES）, X-ray phot...The chemical composition and semi-conductive properties of passive film on nickel- based alloy （G3 alloy） in bicarbonate/carbonate buffer solution were investigated by Auger electron spectroscopy （AES）, X-ray photoelectron spectroscopy （XPS）, elec- trochemical impedance spectra （EIS） and Mott-Schottky plot. AES and XPS results showed that the passive film appeared double-layer structure, in which the inner film was composed of nickel oxide, the mixed nickel-chromium-molybdenum-manganese oxides were the major component of the outer film. The electrochemical results revealed that the factors including frequency, potential, time, temperature and pH value can affect the semi-conductive property, the doping densities decreased with increasing potential and pH value, prolonging time and decreasing temperature. According to the above results, it can be concluded that the film protection on the substrate was enhanced with increasing potential and pH value, prolonging time and decreasing temperature.展开更多
基金Supported by the National Natural Science Foun-dation of China (60374008)
文摘Reconfigurable computing has grown to become an important and large field of research, it offers advantages over traditional hardware and software implementations of computational algorithms. The Advanced Encryption Standard （AES） algorithm is widely applied in government department and commerce. This paper analyzed the AES algorithms with different cipher keys, adopted a novel key scheduler that generated the round key real-time, proposed a dynamically reconfigurable encryption system which supported the AES algorithm with different cipher keys, and designed the architecture of the reconfigurable system. The dynamically reconfigurable AES system had been realized on FPGA. The result proves that the reconfigurable AES system is flexible, lower cost and high security level.
基金Supported by the National Natural Science Foun-dation of China(60503010) and the Foundation of National Laboratory for Modern communications(51436030105DZ0105)
文摘A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential probability （LDP）. Moreover, we present a new method for upper bounding the maximum linear-differential probability （MLDP） for 2 rounds of substitution permutation network （SPN） cipher structure. When our result applies to 2-round advanced encryption standard（AES）, It is shown that the upper bound of MLDP is up to 1.68×2^-19, which extends the known results for the 2-round SPN. Furthermore, when using a recursive technique, we obtain that the MLDP for 4 rounds of AES is bounded by 2^-73.
基金the National Natural Science Foundation of China (No.50501011, G 2000067207-1)Postdoctoral Research Foundation of China (37th batch, No.2005037079)
文摘The specimens were implanted with aluminum ions with fluence ranging from 1× 10^16 to 1× 10^17 ions/cm^2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by metal vapor vacuum arc source （MEVVA） at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）, respectively. Transmission electron microscopy （TEM） was used to examine the microstructure of the aluminum-implanted samples. Glancing angle X-ray diffraction （GAXRD） was employed to examine the phase transformation due to the aluminum ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-2 in a 1 M H2SO4 solution. It is found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-2 implanted with aluminum ions. Finally, the mechanism of the corrosion behavior of aluminum- implanted zircaloy-2 was discussed.
基金This work was financially supported by the National Natural Science Foundation of China (No.50501011), the Ministry of Science andTechnology of China for Research Founding (MSTC No.G 2000067207-1), and the Postdoctoral Research Foundation of China (37thbatch, No.2005037079).
文摘In order to study the effect of copper ion implantation on the aqueous corrosion behavior of ZIRLO alloy, specimens were implanted with copper ions with fluences ranging from 1×10^16 to 1×10^ ions/cm^2, using a metal vapor vacuum arc source （MEVVA） at an extraction voltage of 40 kV, The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）, respectively. Glancing angle X-ray diffraction （GAXRD） was employed to examine the phase transformation due to the copper ion implantation. The potcntiodynamic polarization technique was used to evaluate the aqueous corrosion resistance of implanted ZIRLO alloy in a 1 mol/L H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of ZIRLO alloy implanted with copper ions when the fluence is 5×10^16 ions/cm^2. When the fluence is 1×10^16 or 1×10^17 ions/cm^2, the corrosion resistance of implanted sanaples was bad. Finally, the mechanism of the corrosion behavior of copper-implanted ZIRLO alloy was discussed.
基金supported by the National Natural Science Foundation of China (60973034)the Program for New Century Excellent Talents in University (NCET-07-0328)
文摘Application of embedded systems is faced with multiple threats against security. To solve this problem, this article proposes a new program memory encryption mechanism （PEM） to enhance the security of embedded processor. The new mechanism encrypts all the programs via a secure cache structure. It not only caches the instructions read from the off-chip memory, but also stores the pad values used to encrypt the plaintext. It effectively accelerates encryption and reduces the performance overhead. Besides the encryption, PEM also monitors the program modifications and reset behaviors to reduce the risk of vicious tamper. The experiment indicates that PEM has an average of 2.3 % performance improvement and results in a 25.71% power reduction in the write-back stage. The new scheme offers a good balance between performance and security. It is fully practicable for embedded processor.
文摘The chemical composition and semi-conductive properties of passive film on nickel- based alloy （G3 alloy） in bicarbonate/carbonate buffer solution were investigated by Auger electron spectroscopy （AES）, X-ray photoelectron spectroscopy （XPS）, elec- trochemical impedance spectra （EIS） and Mott-Schottky plot. AES and XPS results showed that the passive film appeared double-layer structure, in which the inner film was composed of nickel oxide, the mixed nickel-chromium-molybdenum-manganese oxides were the major component of the outer film. The electrochemical results revealed that the factors including frequency, potential, time, temperature and pH value can affect the semi-conductive property, the doping densities decreased with increasing potential and pH value, prolonging time and decreasing temperature. According to the above results, it can be concluded that the film protection on the substrate was enhanced with increasing potential and pH value, prolonging time and decreasing temperature.
