{ "id": "1105.5852", "version": "v1", "published": "2011-05-30T03:22:20.000Z", "updated": "2011-05-30T03:22:20.000Z", "title": "On Taking r-th Roots without r-th Nonresidues over Finite Fields and Its Applications", "authors": [ "Tsz-Wo Sze" ], "comment": "28 pages", "categories": [ "math.NT" ], "abstract": "We first show a deterministic algorithm for taking $r$-th roots over $\\F_q$ without being given any $r$-th nonresidue, where $\\F_q$ is a finite field with $q$ elements and $r$ is a small prime such that $r^2$ divides of $q-1$. As applications, we illustrate deterministic algorithms over $\\F_q$ for constructing $r$-th nonresidues, constructing primitive elements, solving polynomial equations and computing elliptic curve \"$n$-th roots\", and a deterministic primality test for the generalized Proth numbers. All algorithms are proved without assuming any unproven hypothesis. They are efficient only if all the factors of $q-1$ are small and some primitive roots of unity can be constructed efficiently over $\\F_q$. In some cases, they are the fastest among the known deterministic algorithms.", "revisions": [ { "version": "v1", "updated": "2011-05-30T03:22:20.000Z" } ], "analyses": { "subjects": [ "12Y05", "11Y11", "14H52" ], "keywords": [ "finite field", "r-th nonresidues", "r-th roots", "applications", "illustrate deterministic algorithms" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1105.5852S" } } }