In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment syst...In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment systems are known to use the TDES scheme for the encryption/decryption of data, and hence faster implementations are of great significance. Field Programmable Gate Arrays (FPGAs) offer a new solution for optimizing the performance of applications meanwhile the Triple Data Encryption Standard (TDES) offers a mean to secure information. In this paper we present a pipelined implementation in VHDL, in Electronic Code Book (EBC) mode, of this commonly used cryptography scheme with aim to improve performance. We achieve a 48-stage pipeline depth by implementing a TDES key buffer and right rotations in the DES decryption key scheduler. Using the Altera Cyclone II FPGA as our platform, we design and verify the implementation with the EDA tools provided by Altera. We gather cost and throughput information from the synthesis and timing results and compare the performance of our design to common implementations presented in other literatures. Our design achieves a throughput of 3.2 Gbps with a 50 MHz clock;a performance increase of up to 16 times.展开更多
A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary functi...A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.展开更多
文摘In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment systems are known to use the TDES scheme for the encryption/decryption of data, and hence faster implementations are of great significance. Field Programmable Gate Arrays (FPGAs) offer a new solution for optimizing the performance of applications meanwhile the Triple Data Encryption Standard (TDES) offers a mean to secure information. In this paper we present a pipelined implementation in VHDL, in Electronic Code Book (EBC) mode, of this commonly used cryptography scheme with aim to improve performance. We achieve a 48-stage pipeline depth by implementing a TDES key buffer and right rotations in the DES decryption key scheduler. Using the Altera Cyclone II FPGA as our platform, we design and verify the implementation with the EDA tools provided by Altera. We gather cost and throughput information from the synthesis and timing results and compare the performance of our design to common implementations presented in other literatures. Our design achieves a throughput of 3.2 Gbps with a 50 MHz clock;a performance increase of up to 16 times.
文摘A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.
