排序方式: 共有43条查询结果,搜索用时 31 毫秒
1.
Algebraic properties of cryptosystem PGM 总被引:2,自引:0,他引:2
In the late 1970s Magliveras invented a private-key cryptographic system calledPermutation Group Mappings (PGM). PGM is based on the prolific existence of certain kinds of factorization sets, calledlogarithmic signatures, for finite permutation groups. PGM is an endomorphic system with message space ℤ|G| for a given finite permutation groupG. In this paper we prove several algebraic properties of PGM. We show that the set of PGM transformations ℐ
G
is not closed under functional composition and hence not a group. This set is 2-transitive on ℤ|G| if the underlying groupG is not hamiltonian and not abelian. Moreover, if the order ofG is not a power of 2, then the set of transformations contains an odd permutation. An important consequence of these results
is that the group generated by the set of transformations is nearly always the symmetric group ℒ|G|. Thus, allowing multiple encryption, any permutation of the message space is attainable. This property is one of the strongest
security conditions that can be offered by a private-key encryption system.
S. S. Magliveras was supported in part by NSF/NSA Grant Number MDA904-82-H0001, by U.S. West Communications, and by the Center
for Communication and Information Science of the University of Nebraska. 相似文献
2.
3.
4.
PETER WINKLER 《Cryptologia》2013,37(4):327-332
The surprising discovery that information can be passed both covertly and legally between bridge partners has added a new dimension to the theory of this popular game. In this paper some of the methods are sketched and their cryptologic foundation is described. 相似文献
5.
一种网络支付手段—电子现金 总被引:1,自引:0,他引:1
本文首先介绍了一种网络支持手段-电子现金的性质,然后简要描述了电子现金系统,最后着重分析了支付中应考虑的主要问题及解决方案。 相似文献
6.
7.
R. Creighton Buck 《Computers & Security》1982,1(3):249-254
The Public Cryptography Study Group was created by the American Council on Education in the spring of 1980 to examine concerns expressed by the Director of NSA caused by the rapid growth of interest in cryptology as a means for the protection of data files. Written by a participant in the study, this paper discusses many of the issues that came before the committee, including the danger to security systems produced by inadvertent or malicious disclosure of weak points in the system which would render it ineffective. It concludes by summarizing the recommendations in the final report of the PCSG, and describes the implementation of the voluntary review procedure recently announced by the Director of NSA. The procedures are designed to decrease the danger to public, private and governmental national security, without impeding the growth of nongovernmental research. 相似文献
8.
本文提出了两种新的度量序列的周期稳定性的指标-定周期距离和变周期距离。文中还研究了一些序列的这两种指标的下界,并给出了衡量序列的周期稳定性的一种方法。 相似文献
9.
We present a new serial-parallel concurrent modular-multiplication algorithm and architecture suitable for standard RSA encryption. In the new scheme, multiplication is performed modulo a multiple of the RSA modulus n, which has a diminished-radix form 2
k
-v, where k and v are positive integers and v < n. This design is the first concurrent modular multiplier to use a diminished-radix algorithm and to pipeline concurrent modular-reduction to optimize the clock rate. For a modular multiplier of order ranging from 1 to 10 (number of multiplier bits per clock cycle), a faster clock rate and throughput is possible than with other known designs including those of Brickell, Morita, Sedlak and Golze, and Miyaguchi. Throughput estimates for 512-bit RSA decryption range from 100 kbit/s in a serial mode to 650 kbit/s with a modular multiplier of order 10, at a clock rate of 20 MHz on 1.5 m CMOS. 相似文献
10.
John P. Costas 《Cryptologia》2013,37(2):94-117
The degree of sophistication available in today's programmable personal calculators may be used to provide a practical field cipher capability of significant power. Procedures are presented for key management, key generator cycling alarm, cipher-type selection to match cryptanalytic threat level, and key length options as an answer to key-search attacks. Three basic cipher procedures are presented with special emphasis given to the inherent power of transposition techniques. Four cryptogram examples are included to demonstrate four of the levels of available security offered by the system. 相似文献