Dearing and Zeck (2009) presented a dual algorithm for the problem of the minimum covering ball in R n . Each iteration of their algorithm has a computational complexity of at least O(n 3 ). In this paper we propose a modification to their algorithm that, together with an implementation that uses updates to the QR factorization of a suitable matrix, achieves a O(n 2 ) iteration.Keywords minimum covering ball · smallest enclosing ball · 1-center · minmax location · computational geometry 1 IntroductionConsider a given set of points P = {p 1 , . . ., p m } in the Euclidean space R n . Let . denote the Euclidean norm. The problem of finding the hypersphere B(x, r) = {y ∈ R n : y − x ≤ r} with minimum radius that covers P, which we will refer to as the minimum covering ball (MB) of P, can be formulated asWe will use the notation MB(P) both to refer to the problem of the minimum covering ball of a set P and, depending on the context, also to the corresponding optimal ball.The MB problem, reported to date back to the 19th century (Sylvester, 1857), is an important and active problem in computational geometry and optimization. Applications include facility location, see e.g. Hale and Moberg (