In this paper, we re-formalize the security notions of universal designated multi verifier signature （UDMVS） schemes. Then the first UDMVS scheme is presented in the standard model （i.e. without random oracles） ba...In this paper, we re-formalize the security notions of universal designated multi verifier signature （UDMVS） schemes. Then the first UDMVS scheme is presented in the standard model （i.e. without random oracles） based on Waters＇ signature scheme. In this setting, a signature holder can to designate the signature to multi verifiers. Moreover, the security of our proposed scheme is based on the Gap Bilinear Difffie-Hellman assumption.展开更多
This paper focuses on the instantiation of random oracles in public key encryption schemes. A misunderstanding in the former instantiations is pointed out and analyzed. A method of using this primitive as a substituti...This paper focuses on the instantiation of random oracles in public key encryption schemes. A misunderstanding in the former instantiations is pointed out and analyzed. A method of using this primitive as a substitution of random oracles is also proposed. The partial and full instantiations of random oracles in optimal asymmetric encryption padding （OAEP） implemented by pseudorandom functions are described and the resulted schemes are proven to be indistinguishable secure against adaptive chosen ciphertext attack （IND-CCA2） secure. Using this method, one can transform a practical public key encryption scheme secure in the random oracle model into a standard-model secure scheme. The security of the scheme is based on computational assumptions, which is weaker than decisional assumptions used in Cramer- Shoup like schemes.展开更多
In this paper,we present an identity-based explicit authenticated key agreement protocol that is provably secure without random oracles.The protocol employs a new method to isolate a session key from key confirmation ...In this paper,we present an identity-based explicit authenticated key agreement protocol that is provably secure without random oracles.The protocol employs a new method to isolate a session key from key confirmation keys so that there is no direct usage of hash functions in the protocol.The protocol is proved secure without random oracles in a variant of Bellare and Rogaway style model,an exception to current proof method in this style model in the ID-based setting.We believe that this key isolation method is novel and can be further studied for constructing more efficient protocols.展开更多
The research on the identification scheme is an important and active area in computer and communication security. A series of identification schemes were proposed to improve the efficiency and security of the protocol...The research on the identification scheme is an important and active area in computer and communication security. A series of identification schemes were proposed to improve the efficiency and security of the protocols by various methods. Based on the hardness assumption of the discrete logarithm problem in a gap Diffie-Hellman group and the difficulty of the collusion attack algorithm with k traitors, an efficient identification scheme is presented. Without random oracle models, the proposed scheme is then proved secure against impersonation and reset attacks in both concurrent and reset attack setting. Since the proposed scheme is simple, memory-saving, computation-efficient, and perfectly-secure, it is well suitable for use in smart cards.展开更多
The first major exhibition in the US dedicated to China's ancient capital 3,000 years ago carries key codes to the origin of the Chinese civilization and modern archaeological works,as well as the China-US cultura...The first major exhibition in the US dedicated to China's ancient capital 3,000 years ago carries key codes to the origin of the Chinese civilization and modern archaeological works,as well as the China-US cultural relations in the future。展开更多
新疆维吾尔自治区地震地下流体观测资料是地震形势研判的重要依据。Ms5.0以上地震发生后,流体资料需要快速自动产出。采用Python语言编写新疆地区地震流体观测资料的快速产出脚本程序,可以实现紧急会商资料的快速产出。利用Python丰富的...新疆维吾尔自治区地震地下流体观测资料是地震形势研判的重要依据。Ms5.0以上地震发生后,流体资料需要快速自动产出。采用Python语言编写新疆地区地震流体观测资料的快速产出脚本程序,可以实现紧急会商资料的快速产出。利用Python丰富的包,包括Requests实现地震目录的爬取、cx_Oracle连接数据库及数据下载、pandas实现数据的筛选清洗、matplotlib实现数据成图及震例标注,再利用Python-pptx可以产出紧急会商所需要的PPT。通过对程序流程的控制,最终实现新疆流体资料紧急会商的自动产出。测试运行结果显示:可在1 min 40 s内完成新疆流体102项资料周会商和紧急会商PPT资料的产出。展开更多
With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become ...With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become a research hotspot, and the security of the oracle responsible for providing reliable data has attracted much attention. The most widely used centralized oracles in blockchain, such as Provable and Town Crier, all rely on a single oracle to obtain data, which suffers from a single point of failure and limits the large-scale development of blockchain. To this end, the distributed oracle scheme is put forward, but the existing distributed oracle schemes such as Chainlink and Augur generally have low execution efficiency and high communication overhead, which leads to their poor applicability. To solve the above problems, this paper proposes a trusted distributed oracle scheme based on a share recovery threshold signature. First, a data verification method of distributed oracles is designed based on threshold signature. By aggregating the signatures of oracles, data from different data sources can be mutually verified, leading to a more efficient data verification and aggregation process. Then, a credibility-based cluster head election algorithm is designed, which reduces the communication overhead by clarifying the function distribution and building a hierarchical structure. Considering the good performance of the BLS threshold signature in large-scale applications, this paper combines it with distributed oracle technology and proposes a BLS threshold signature algorithm that supports share recovery in distributed oracles. The share recovery mechanism enables the proposed scheme to solve the key loss issue, and the setting of the threshold value enables the proposed scheme to complete signature aggregation with only a threshold number of oracles, making the scheme more robust. Finally, experimental results indicate that, by using the threshold signature technology and the cluster head election algorithm, our scheme effectively improves the execution efficiency of oracles and solves the problem of a single point of failure, leading to higher scalability and robustness.展开更多
基金Supported by the National Natural Science Foundation of China (60772136)
文摘In this paper, we re-formalize the security notions of universal designated multi verifier signature （UDMVS） schemes. Then the first UDMVS scheme is presented in the standard model （i.e. without random oracles） based on Waters＇ signature scheme. In this setting, a signature holder can to designate the signature to multi verifiers. Moreover, the security of our proposed scheme is based on the Gap Bilinear Difffie-Hellman assumption.
基金Supported by the National Basic Research Program of China (973 Program) (2007CB311201)the National High-Technology Research and Development Program of China (863 Program) (2006AA01Z427)the National Natural Science Foundation of China (60673073)
文摘This paper focuses on the instantiation of random oracles in public key encryption schemes. A misunderstanding in the former instantiations is pointed out and analyzed. A method of using this primitive as a substitution of random oracles is also proposed. The partial and full instantiations of random oracles in optimal asymmetric encryption padding （OAEP） implemented by pseudorandom functions are described and the resulted schemes are proven to be indistinguishable secure against adaptive chosen ciphertext attack （IND-CCA2） secure. Using this method, one can transform a practical public key encryption scheme secure in the random oracle model into a standard-model secure scheme. The security of the scheme is based on computational assumptions, which is weaker than decisional assumptions used in Cramer- Shoup like schemes.
基金supported by the National Natural Science Foundation of China under Grant No.60473027by Sun Yat-Sen University under Grant Nos.35000-2910025 and 35000-3171912.
文摘In this paper,we present an identity-based explicit authenticated key agreement protocol that is provably secure without random oracles.The protocol employs a new method to isolate a session key from key confirmation keys so that there is no direct usage of hash functions in the protocol.The protocol is proved secure without random oracles in a variant of Bellare and Rogaway style model,an exception to current proof method in this style model in the ID-based setting.We believe that this key isolation method is novel and can be further studied for constructing more efficient protocols.
基金supported by the National Natural Science Foundation of China (60803151)the Major Joint Research Foundation of NSFC and Guangdong Province (U0835004).
文摘The research on the identification scheme is an important and active area in computer and communication security. A series of identification schemes were proposed to improve the efficiency and security of the protocols by various methods. Based on the hardness assumption of the discrete logarithm problem in a gap Diffie-Hellman group and the difficulty of the collusion attack algorithm with k traitors, an efficient identification scheme is presented. Without random oracle models, the proposed scheme is then proved secure against impersonation and reset attacks in both concurrent and reset attack setting. Since the proposed scheme is simple, memory-saving, computation-efficient, and perfectly-secure, it is well suitable for use in smart cards.
文摘The first major exhibition in the US dedicated to China's ancient capital 3,000 years ago carries key codes to the origin of the Chinese civilization and modern archaeological works,as well as the China-US cultural relations in the future。
文摘新疆维吾尔自治区地震地下流体观测资料是地震形势研判的重要依据。Ms5.0以上地震发生后,流体资料需要快速自动产出。采用Python语言编写新疆地区地震流体观测资料的快速产出脚本程序,可以实现紧急会商资料的快速产出。利用Python丰富的包,包括Requests实现地震目录的爬取、cx_Oracle连接数据库及数据下载、pandas实现数据的筛选清洗、matplotlib实现数据成图及震例标注,再利用Python-pptx可以产出紧急会商所需要的PPT。通过对程序流程的控制,最终实现新疆流体资料紧急会商的自动产出。测试运行结果显示:可在1 min 40 s内完成新疆流体102项资料周会商和紧急会商PPT资料的产出。
基金supported by the National Natural Science Foundation of China(Grant No.62102449)the Central Plains Talent Program under Grant No.224200510003.
文摘With the increasing popularity of blockchain applications, the security of data sources on the blockchain is gradually receiving attention. Providing reliable data for the blockchain safely and efficiently has become a research hotspot, and the security of the oracle responsible for providing reliable data has attracted much attention. The most widely used centralized oracles in blockchain, such as Provable and Town Crier, all rely on a single oracle to obtain data, which suffers from a single point of failure and limits the large-scale development of blockchain. To this end, the distributed oracle scheme is put forward, but the existing distributed oracle schemes such as Chainlink and Augur generally have low execution efficiency and high communication overhead, which leads to their poor applicability. To solve the above problems, this paper proposes a trusted distributed oracle scheme based on a share recovery threshold signature. First, a data verification method of distributed oracles is designed based on threshold signature. By aggregating the signatures of oracles, data from different data sources can be mutually verified, leading to a more efficient data verification and aggregation process. Then, a credibility-based cluster head election algorithm is designed, which reduces the communication overhead by clarifying the function distribution and building a hierarchical structure. Considering the good performance of the BLS threshold signature in large-scale applications, this paper combines it with distributed oracle technology and proposes a BLS threshold signature algorithm that supports share recovery in distributed oracles. The share recovery mechanism enables the proposed scheme to solve the key loss issue, and the setting of the threshold value enables the proposed scheme to complete signature aggregation with only a threshold number of oracles, making the scheme more robust. Finally, experimental results indicate that, by using the threshold signature technology and the cluster head election algorithm, our scheme effectively improves the execution efficiency of oracles and solves the problem of a single point of failure, leading to higher scalability and robustness.
