The Godson project is the first attempt to design high performancegeneral-purpose microprocessors in China. This paper introduces the microarchitecture of theGodson-2 processor which is a 64-bit, 4-issue, out-of-order...The Godson project is the first attempt to design high performancegeneral-purpose microprocessors in China. This paper introduces the microarchitecture of theGodson-2 processor which is a 64-bit, 4-issue, out-of-order execution RISC processor that implementsthe 64-bit MIPS-like instruction set. The adoption of the aggressive out-of-order executiontechniques (such as register mapping, branch prediction, and dynamic scheduling) and cachetechniques (such as non-blocking cache, load speculation, dynamic memory disambiguation) helps theGodson-2 processor to achieve high performance even at not so high frequency. The Godson-2 processorhas been physically implemented on a 6-metal 0.18 μm CMOS technology based on the automaticplacing and routing flow with the help of some crafted library cells and macros. The area of thechip is 6,700 micrometers by 6,200 micrometers and the clock cycle at typical corner is 2.3 ns.展开更多
Social computing, as the technical foundation of future computational smart societies, has the potential to improve the effectiveness of opensource big data usage, systematically integrate a variety of elements includ...Social computing, as the technical foundation of future computational smart societies, has the potential to improve the effectiveness of opensource big data usage, systematically integrate a variety of elements including time, human, resources, scenarios, and organizations in the current cyber-physical-social world, and establish a novel social structure with fair information, equal rights, and a flat configuration. Meanwhile, considering the big modeling gap between the model world and the physical world, the concept of parallel intelligence is introduced. With the help of software-defined everything, parallel intelligence bridges the big modeling gap by means of constructing artificial systems where computational experiments can be implemented to verify social policies, economic strategies, and even military operations. Artificial systems play the role of ＂social laboratories＂ in which decisions are computed before they are executed in our physical society. Afterwards, decisions with the expected outputs are executed in parallel in both the artificial and physical systems to interactively sense, compute, evaluate and adjust system behaviors in real-time, leading system behaviors in the physical system converging to those proven to be optimal in the artificial ones. Thus, the smart guidance and management for our society can be achieved.展开更多
Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts...Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.展开更多
文摘The Godson project is the first attempt to design high performancegeneral-purpose microprocessors in China. This paper introduces the microarchitecture of theGodson-2 processor which is a 64-bit, 4-issue, out-of-order execution RISC processor that implementsthe 64-bit MIPS-like instruction set. The adoption of the aggressive out-of-order executiontechniques (such as register mapping, branch prediction, and dynamic scheduling) and cachetechniques (such as non-blocking cache, load speculation, dynamic memory disambiguation) helps theGodson-2 processor to achieve high performance even at not so high frequency. The Godson-2 processorhas been physically implemented on a 6-metal 0.18 μm CMOS technology based on the automaticplacing and routing flow with the help of some crafted library cells and macros. The area of thechip is 6,700 micrometers by 6,200 micrometers and the clock cycle at typical corner is 2.3 ns.
文摘Social computing, as the technical foundation of future computational smart societies, has the potential to improve the effectiveness of opensource big data usage, systematically integrate a variety of elements including time, human, resources, scenarios, and organizations in the current cyber-physical-social world, and establish a novel social structure with fair information, equal rights, and a flat configuration. Meanwhile, considering the big modeling gap between the model world and the physical world, the concept of parallel intelligence is introduced. With the help of software-defined everything, parallel intelligence bridges the big modeling gap by means of constructing artificial systems where computational experiments can be implemented to verify social policies, economic strategies, and even military operations. Artificial systems play the role of ＂social laboratories＂ in which decisions are computed before they are executed in our physical society. Afterwards, decisions with the expected outputs are executed in parallel in both the artificial and physical systems to interactively sense, compute, evaluate and adjust system behaviors in real-time, leading system behaviors in the physical system converging to those proven to be optimal in the artificial ones. Thus, the smart guidance and management for our society can be achieved.
基金This work was supported by the National Key Research and Development Program of China under Grant No. 2016YFB1000104, the National Natural Science Foundation of China under Grant Nos. 61572314 and 61525204, and the Young Scientists Fund of the National Natural Science Foundation of China under Grant No. 61303011.
文摘Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.
