Fast recognition of doubly transitive groups

The availability of the classification of finite simple groups allows us to design algorithms for identifying the composition factors of finite groups. This paper presents an algorithm which identifies any finite doubly transitive permutation group G. If we exclude the 2-transitive subgroups of the one-dimensional affine group and 14 small exceptional groups, the cost of our algorithm is essentially the cost of constructing a base and strong generating set for G. Consequently, our algorithm avoids the need to compute the soluble residual of G as required by Kantor's composition factors algorithm for a general permutation group.