End hopping is an active and effective technology for defending against adversaries in the network warfare.Synchronization is a key technology of end hopping.However,the common synchronization methods are insufficient...End hopping is an active and effective technology for defending against adversaries in the network warfare.Synchronization is a key technology of end hopping.However,the common synchronization methods are insufficient for end hopping.Based on timestamp synchronization,this paper proposes a novel method of Distributed Timestamp Synchronization(DTS)to improve the capacity of synchronization.DTS uses a list of timestamp servers which are located all over the Internet to synchronize timestamp,and a list of clock offsets to adjust the synchronized timestamp.DTS can overcome the main deficiencies(request overwhelming and boundary failure)of timestamp synchronization.Experiments show that DTS is a feasible synchronization technology for end hopping.展开更多
A measurement method of optical fiber length using timestamp technique is demonstrated. Based on IEEE1588 precise clock synchronization protocol, the principle that time delay asymmetry on two path results in synchr...A measurement method of optical fiber length using timestamp technique is demonstrated. Based on IEEE1588 precise clock synchronization protocol, the principle that time delay asymmetry on two path results in synchronization time deviation is used, and the difference between two-path delays could be deduced by measuring the synchronization time deviation reversely. Then the length of optical fiber on one path could be calculated if that on the other path is known Due to the fact that the path of Sync and Delay_Req message is symmetric, the optical pulse dispersion and the asymmetry of photoelectric detector performance on two paths are averaged by exchanging two optical fibers. The time difference between master and slave clocks is eliminated by sharing the same time base. At last, the lengths of two single-mode optical fibers are measured with the uncertainty of 0. 578 m for 3 227. 722 m and 0. 758 m for 25 491. 522 m, respectively. Thus this method has high precision and long range.展开更多
In the data communication system,the real-time information interaction of communication device increases the risk of privacy sensitive data being tam-pered with.Therefore,maintaining data security is one of the most i...In the data communication system,the real-time information interaction of communication device increases the risk of privacy sensitive data being tam-pered with.Therefore,maintaining data security is one of the most important issues in network data communication.Because the timestamp is the most impor-tant way to authenticate data in information interaction,it is very necessary to pro-vide timestamp service in the data communication system.However,the existing centralized timestamp mechanism is difficult to provide credible timestamp ser-vice,and users can conspire with timestamping servers to forge timestamps.Therefore,this paper designs a distributed timestamp mechanism based on contin-uous verifiable delay functions.It utilizes multiple independent timestamp servers to provide timestamp services in a distributed model and appends the timestamp to the data once the data is generated.Thus,it can prove that the data already exists at a certain time and ensure the accuracy of the timestamp.Moreover,a digital blind signature based on elliptic curve cryptography is utilized to solve the problem of timestamp forgery in timestamp service.Finally,the security ana-lysis of the scheme ensures the data security of data communication system and the concurrency rate of timestamp.The experimental results also show that the scheme greatly improves the efficiency of digital signatures.展开更多
The power infrastructure of the power system is massive in size and dispersed throughout the system.Therefore,how to protect the information security in the operation and maintenance of power equipment is a difficult ...The power infrastructure of the power system is massive in size and dispersed throughout the system.Therefore,how to protect the information security in the operation and maintenance of power equipment is a difficult problem.This paper proposes an improved time-stamped blockchain technology biometric fuzzy feature for electrical equipment maintenance.Compared with previous blockchain transactions,the time-stamped fuzzy biometric signature proposed in this paper overcomes the difficulty that the key is easy to be stolen by hackers and can protect the security of information during operation and maintenance.Finally,the effectiveness of the proposed method is verified by experiments.展开更多
Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocol...Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocols rely on computational assumptions for security,rendering them vulnerable to quantum attacks,which is a critical limitation given the rapid progress in quantum computing.To address this,we propose an information-theoretically secure quantum timestamping protocol based on one-time universal hashing with quantum keys.Our protocol simultaneously achieves information-theoretic security and high efficiency,enabling secure timestamping for arbitrarily long documents.Simulations demonstrate a generation rate exceeding 100 timestamps per second over intercity distances.In addition,our protocol only requires weak coherent states,making it practical for large-scale deployment.This work advances the field of quantum timestamping and contributes to the broader development of quantum cryptography and the future quantum internet.展开更多
Timestamps play a key role in process mining because it determines the chronology of which events occurred and subsequently how they are ordered in process modelling.The timestamp in process mining gives an insight on...Timestamps play a key role in process mining because it determines the chronology of which events occurred and subsequently how they are ordered in process modelling.The timestamp in process mining gives an insight on process performance,conformance,and modelling.This therefore means problems with the timestamp will result in misrepresentations of the mined process.A few articles have been published on the quantification of data quality problems but just one of the articles at the time of this paper is based on the quantification of timestamp quality problems.This article evaluates the quality of timestamps in event log across two axes using eleven quality dimensions and four levels of potential data quality problems.The eleven data quality dimensions were obtained by doing a thorough literature review of more than fifty process mining articles which focus on quality dimensions.This evaluation resulted in twelve data quality quantification metrics and the metrics were applied to the MIMIC-ll dataset as an illustration.The outcome of the timestamp quality quantification using the proposed typology enabled the user to appreciate the quality of the event log and thus makes it possible to evaluate the risk of carrying out specific data cleaning measures to improve the process mining outcome.展开更多
Serializable snapshot isolation(SSI)is a promising technique to exploit parallelism for multi-core databases.However,SSI suffers from excessive transaction aborts.Existing remedies have three drawbacks:1)tracking proh...Serializable snapshot isolation(SSI)is a promising technique to exploit parallelism for multi-core databases.However,SSI suffers from excessive transaction aborts.Existing remedies have three drawbacks:1)tracking prohibitively transitive dependencies;2)aborting on every writewrite conflict;and 3)requiring manual annotation on transaction programs.In this paper,we propose to suppress transaction aborts by reassigning timestamps.We combine static analysis with augmented query plan.In this way,we save both aborts caused by read-write and write-write conflicts,without tracking transitive dependency and annotating transaction programs.As such,our approach does not exhibit drawbacks of existing methods.Extensive experiments demonstrate the effectiveness and practicality of our approach.展开更多
A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)paramet...A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)parametrization was developed to adapt to different experimental sizes.A user-friendly interface was implemented,which allows converting script language expressions into FPGA internal control parameters.The proposed digital system can be combined with a conventional analog data acquisition system to provide more flexibility.The performance of the combined system was veri-fied using experimental data.展开更多
基金National Natural Science Foundation of China under Grant No. 60973141Natural Science Foundation of Tianjin under Grant No. 09JCYBJ00300Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20100031110030
文摘End hopping is an active and effective technology for defending against adversaries in the network warfare.Synchronization is a key technology of end hopping.However,the common synchronization methods are insufficient for end hopping.Based on timestamp synchronization,this paper proposes a novel method of Distributed Timestamp Synchronization(DTS)to improve the capacity of synchronization.DTS uses a list of timestamp servers which are located all over the Internet to synchronize timestamp,and a list of clock offsets to adjust the synchronized timestamp.DTS can overcome the main deficiencies(request overwhelming and boundary failure)of timestamp synchronization.Experiments show that DTS is a feasible synchronization technology for end hopping.
基金National Natural Science Foundation of China(No.61271120/F010508)National Science and Technology Support Program(No.2014BAK02BO2,No.2014BAK02BO5)National Science and Technology Major Projects(broadband wireless2015ZX03001011-002)
文摘A measurement method of optical fiber length using timestamp technique is demonstrated. Based on IEEE1588 precise clock synchronization protocol, the principle that time delay asymmetry on two path results in synchronization time deviation is used, and the difference between two-path delays could be deduced by measuring the synchronization time deviation reversely. Then the length of optical fiber on one path could be calculated if that on the other path is known Due to the fact that the path of Sync and Delay_Req message is symmetric, the optical pulse dispersion and the asymmetry of photoelectric detector performance on two paths are averaged by exchanging two optical fibers. The time difference between master and slave clocks is eliminated by sharing the same time base. At last, the lengths of two single-mode optical fibers are measured with the uncertainty of 0. 578 m for 3 227. 722 m and 0. 758 m for 25 491. 522 m, respectively. Thus this method has high precision and long range.
基金supported by National Key R&D Program of China(Grant Nos.2021YF B2700503,2020YF B1005900)supported by the National Natural Science Foundation of China(No.62072249)。
文摘In the data communication system,the real-time information interaction of communication device increases the risk of privacy sensitive data being tam-pered with.Therefore,maintaining data security is one of the most important issues in network data communication.Because the timestamp is the most impor-tant way to authenticate data in information interaction,it is very necessary to pro-vide timestamp service in the data communication system.However,the existing centralized timestamp mechanism is difficult to provide credible timestamp ser-vice,and users can conspire with timestamping servers to forge timestamps.Therefore,this paper designs a distributed timestamp mechanism based on contin-uous verifiable delay functions.It utilizes multiple independent timestamp servers to provide timestamp services in a distributed model and appends the timestamp to the data once the data is generated.Thus,it can prove that the data already exists at a certain time and ensure the accuracy of the timestamp.Moreover,a digital blind signature based on elliptic curve cryptography is utilized to solve the problem of timestamp forgery in timestamp service.Finally,the security ana-lysis of the scheme ensures the data security of data communication system and the concurrency rate of timestamp.The experimental results also show that the scheme greatly improves the efficiency of digital signatures.
基金This research was funded by science and technology project of State Grid JiangSu Electric Power Co.,Ltd.(Research on Key Technologies of power network security digital identity authentication and management and control based on blockchain,Grant No.is J2021021).
文摘The power infrastructure of the power system is massive in size and dispersed throughout the system.Therefore,how to protect the information security in the operation and maintenance of power equipment is a difficult problem.This paper proposes an improved time-stamped blockchain technology biometric fuzzy feature for electrical equipment maintenance.Compared with previous blockchain transactions,the time-stamped fuzzy biometric signature proposed in this paper overcomes the difficulty that the key is easy to be stolen by hackers and can protect the security of information during operation and maintenance.Finally,the effectiveness of the proposed method is verified by experiments.
基金supported by the National Natural Science Foundation of China(Grant No.12274223)the Program for Innovative Talents,Entrepreneurs in Jiangsu(Grant No.JSSCRC2021484)the Key Research and Development Program of Nanjing Jiangbei New Area(Grant No.ZDYD20210101)。
文摘Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering,such as legal documentation and digital intellectual property protection.Classical timestamp protocols rely on computational assumptions for security,rendering them vulnerable to quantum attacks,which is a critical limitation given the rapid progress in quantum computing.To address this,we propose an information-theoretically secure quantum timestamping protocol based on one-time universal hashing with quantum keys.Our protocol simultaneously achieves information-theoretic security and high efficiency,enabling secure timestamping for arbitrarily long documents.Simulations demonstrate a generation rate exceeding 100 timestamps per second over intercity distances.In addition,our protocol only requires weak coherent states,making it practical for large-scale deployment.This work advances the field of quantum timestamping and contributes to the broader development of quantum cryptography and the future quantum internet.
文摘Timestamps play a key role in process mining because it determines the chronology of which events occurred and subsequently how they are ordered in process modelling.The timestamp in process mining gives an insight on process performance,conformance,and modelling.This therefore means problems with the timestamp will result in misrepresentations of the mined process.A few articles have been published on the quantification of data quality problems but just one of the articles at the time of this paper is based on the quantification of timestamp quality problems.This article evaluates the quality of timestamps in event log across two axes using eleven quality dimensions and four levels of potential data quality problems.The eleven data quality dimensions were obtained by doing a thorough literature review of more than fifty process mining articles which focus on quality dimensions.This evaluation resulted in twelve data quality quantification metrics and the metrics were applied to the MIMIC-ll dataset as an illustration.The outcome of the timestamp quality quantification using the proposed typology enabled the user to appreciate the quality of the event log and thus makes it possible to evaluate the risk of carrying out specific data cleaning measures to improve the process mining outcome.
基金supported by the National Key R&D Program of China(2018YFB1004401)the National Natural Science Foundation of China Key Project(Grant No.61732014).
文摘Serializable snapshot isolation(SSI)is a promising technique to exploit parallelism for multi-core databases.However,SSI suffers from excessive transaction aborts.Existing remedies have three drawbacks:1)tracking prohibitively transitive dependencies;2)aborting on every writewrite conflict;and 3)requiring manual annotation on transaction programs.In this paper,we propose to suppress transaction aborts by reassigning timestamps.We combine static analysis with augmented query plan.In this way,we save both aborts caused by read-write and write-write conflicts,without tracking transitive dependency and annotating transaction programs.As such,our approach does not exhibit drawbacks of existing methods.Extensive experiments demonstrate the effectiveness and practicality of our approach.
基金This work was supported by the National Key R&D Program of China(Nos.2023YFA1606403 and 2023YFE0101600)the National Natural Science Foundation of China(Nos.12027809,11961141003,U1967201,11875073 and 11875074).
文摘A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)parametrization was developed to adapt to different experimental sizes.A user-friendly interface was implemented,which allows converting script language expressions into FPGA internal control parameters.The proposed digital system can be combined with a conventional analog data acquisition system to provide more flexibility.The performance of the combined system was veri-fied using experimental data.
