In this paper we present a new algorithm for computing the bilinear pairings on a family of non-supersingular elliptic curves with non-trivial automorphisms. We obtain a short iteration loop in Miller’s algorithm using non-trivial efficient automorphisms. The proposed algorithm is as efficient as the algorithm in [12].

We continue the study of twisted automorphisms of Hopf algebras started in [4]. In this paper we concentrate on the group algebra case. We describe the group of twisted automorphisms of the group algebra of a group of order coprime to 6. The description turns out to be very similar to the one for the universal enveloping algebra given in [4].

Let R be a perfect ring of characteristic p. We show that the group of continuous R-linear automorphisms of the perfect power series ring over R is generated by the automorphisms of the ordinary power series ring together with Frobenius; this answers a question of Jared Weinstein.

In mathematics, automorphisms of algebraic structures play an important role. Automorphisms capture the symmetries inherent in the structures and many important results have been proved by analyzing the automorphism group of the structure. For example, Galois characterized degree five univariate polynomials f over rationals whose roots can be expressed using radicals (using addition, subtractio...

Continuing the earlier research [Fund. Math. 129 (1988) and 149 (1996)] we give some information about extending automorphisms of models of PA to cofinal extensions. In recent work on automorphisms of recursively saturated models of PA two themes stand out. One is the classification of conjugacy classes of single automorphisms, the other is the classification of subgroups of the automorphism gr...

This lecture gives background to and results of work of my student John Shrimpton [19, 20, 21]. It advertises the joining of two themes: groups and symmetry; and categorical methods and analogues of set theory. Groups are expected to be associated with symmetry. Klein’s famous Erlanger Programme asserted that the study of a geometry was the study of the group of automorphisms of that geometry. ...

The ElGamal cryptosystem is the most widely used public key cryptosystem. It uses the discrete logarithm problem as the cryptographic primitive. The MOR cryptosystem is a similar cryptosystem. It uses the discrete logarithm problem in the automorphism group as the cryptographic primitive. In this paper, we study the MOR cryptosystem for finite p-groups. The study is complete for p-automorphisms...

We show that the countable universal-homogeneous partial order (P,<) has a generic automorphism as defined by the second author, namely that it lies in a comeagre conjugacy class of Aut(P,<). For this purpose, we work with ‘determined’ partial finite automorphisms that need not be automorphisms of finite substructures (as in the proofs of similar results for other countable homogeneous structur...

We survey some encoding methods for AG codes, focusing primarily on one approach utilizing code automorphisms. If a linear code C over Fq has a finite abelian group H as a group of automorphisms, then C has the structure of a module over a polynomial ring P. This structure can be used to develop systematic encoding algorithms using Gröbner bases for modules. We illustrate these observations wit...

We characterise connected cubic graphs admitting a vertextransitive group of automorphisms with an abelian normal subgroup that is not semiregular. We illustrate the utility of this result by using it to prove that the order of a semiregular subgroup of maximum order in a vertex-transitive group of automorphisms of a connected cubic graph grows with the order of the graph, settling [2, Problem ...