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Random covers for finite groups have been introduced in Magliveras et al. (J Cryptol 15:285-297, ), Lempken et al. (J Cryptol 22:62-74, ), and Svaba and van Trung (J Math Cryptol 4:271-315, ) for constructing public key cryptosystems. In this article we describe a new approach for constructing pseudorandom number generators using random covers for large finite groups. We focus, in particular, on the class of elementary abelian 2-groups and study the randomness of binary sequences generated from these generators. We successfully carry out an extensive test of the generators by using the NIST Statistical Test Suite and the Diehard battery of tests. Moreover, the article presents argumentation showing that the generators are suitable for cryptographic applications. Finally, we include performance data of the generators and propose a method of using them in practice. [ABSTRACT FROM AUTHOR]

A new type of public key cryptosystem, called MST3, has been recently introduced on the basis of covers and logarithmic signatures for non-abelian finite groups. The class of Suzuki 2-groups has been proposed for a possible realization of the generic scheme. Due to their simple structure, the groups enable us to study the security of the system and also provide an efficient implementation. An earlier relevant result of the cryptanalysis has shown that the transversal logarithmic signatures are unfit for use in this realization. In this paper we present a revised version of MST3 for the Suzuki 2-groups and show a thorough study of its security. Using heuristic and algebraic methods we establish strong lower bounds for the workload of conceivable direct attacks on the private key of the scheme. We then develop a powerful chosen plaintext attack which allows us to rule out the usage of a certain class of logarithmic signatures. In addition, we show a class of logarithmic signatures withstanding this attack and thus to our knowledge they could be used in the realization of the scheme. Finally, we describe and discuss the implementation issues of the scheme in detail and include data of its performance obtained from an experimental result. [ABSTRACT FROM AUTHOR]