排序方式: 共有84条查询结果,搜索用时 42 毫秒
61.
基于J2EE WebGIS的一种空间数据管理方法 总被引:1,自引:0,他引:1
在阐述基于J2EE的WebGIS概念、体系结构以及Oracle9i spatial的原理、新特性的基础上,结合具体实例给出了一种用oracle9i spatial臬解决J2EEWebGIS下的空间数据库实现技术。 相似文献
62.
研究相对化的P=?NP问题,提出了矛盾天书、相对天书和绝对天书的概念,证明了这些天书的客观存在性,并具体地构造了一个矛盾天书和一个NP集类之外的相对天书.结论对利用现有关于相对化P=?NP问题的成果来研究NP问题将产生有益的影响 相似文献
63.
《河南师范大学学报(自然科学版)》2016,(1):155-160
通过对一个基于身份的部分盲签名方案的分析,指出其存在公共信息被非法篡改的漏洞.针对这一问题,在原方案的基础上进行改进,提出一个新的部分盲签名方案.证明了改进方案的正确性、公共信息不可篡改性和部分盲性,并利用随机预言机模型证明了方案在适应性选择消息和身份攻击下是存在性不可伪造的. 相似文献
64.
In this paper, an efficient hybrid proxy re-encryption scheme that allows the transformation of the ciphertexts in a traditional public key cryptosystem into the ciphertexts in an identity-based system is proposed. The scheme is non-interactive, unidirectional and collude "safe". Furthermore, it is compatible with current IBE (identity-based encryption) deployments. The scheme has chosen ciphertext security in the random oracle model assuming the hardness of the Decisional Bilinear Diffie-Hellman problem. 相似文献
65.
基于强RSA假设的数字签名方案 总被引:2,自引:0,他引:2
针对基于强RSA(Riverst,Shamir,Adleman)假设的数字答名方案,首先通过哈希函数潜在性质分析现有方案的安全缺陷,然后通过删除冗余参数x和采用一个生成元简化签名方案,最后在强RSA假设和签名预言机模型下证明该方案是安全的.新方案弥补了安全漏洞,比以往的方案更简洁、高效且安全. 相似文献
66.
熊虎 《高技术通讯(英文版)》2009,15(1):94-100
Identity-based (ID-based) ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings. 相似文献
67.
68.
陈汉军萨满祭祀是在清代八旗制度的基础上,满、汉文化互相影响和融合,形成的一种不同于满族萨满祭祀和汉族民香的独特的祭祀活动。陈汉军旗的萨满神谕作为陈汉军旗萨满祭祀神歌、仪式的基本载体,和满族萨满神谕、民香香卷相比,亦具有其自身独特的特点。 相似文献
69.
To support withdrawing and storing money from all levels of the bank for the customers in the real world, in this paper, we propose a proxy blind signature scheme and an off-line e-cash scheme based on the new proxy blind signature scheme. The proposed proxy blind signature is proven secure in the random oracle model under chosen-target computational Diffie-Hellman assumptions, and the e-cash scheme can satisfy the security requirements of unforgeability, anonymity, and traceability. 相似文献
70.
利用ORACLE物化视图技术,结合在电力营销系统运行实践中遇到的数据库应用优化问题,清晰且详细地从数据库性能问题的定位、分析和解决等方面进行了论述,对类似电力营销业务的项目和工程,具有较高的实际参考价值。 相似文献