From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Noob dumb question (extending emacs) Date: Mon, 01 Nov 2021 03:09:54 +0100 Message-ID: <878ry8vd71.fsf@zoho.eu> References: <86k0i6uoxd.fsf@duenenhof-wilhelm.de> <871r4ernmt.fsf@zoho.eu> <87o87hnrpt.fsf@zoho.eu> <87y26kkuag.fsf@web.de> <87zgr0t3vw.fsf@web.de> <87o87fy4t3.fsf@zoho.eu> <87ilxmsuqq.fsf@web.de> <87k0hxj37u.fsf@zoho.eu> <878rydbcm4.fsf@web.de> <8735okj2bx.fsf@zoho.eu> <87fsskzroz.fsf@zoho.eu> <877ddsgbx0.fsf@web.de> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="38384"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:hiWu9FYuHrH/M30OsjzwMRepQH0= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Mon Nov 01 03:10:37 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mhMmS-0009lV-Lj for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 01 Nov 2021 03:10:36 +0100 Original-Received: from localhost ([::1]:35792 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mhMmR-0006qC-Dd for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 31 Oct 2021 22:10:35 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50460) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mhMlz-0006q2-Ey for help-gnu-emacs@gnu.org; Sun, 31 Oct 2021 22:10:08 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:58660) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mhMlx-0001vh-Aw for help-gnu-emacs@gnu.org; Sun, 31 Oct 2021 22:10:07 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mhMlv-0009D2-De for help-gnu-emacs@gnu.org; Mon, 01 Nov 2021 03:10:03 +0100 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.248, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:134282 Archived-At: Michael Heerdegen wrote: >> See below, if we remain at 48 bits of entropy, but instead >> of 60 have an alphabet of only 3 chars, the password length >> rises from 8.13 chars to 30.28 ... >> >> Does this tell us that it is equally difficult to randomly >> guess the both passwords from the two different >> configuration at these lengths, or what does it tell us? > > If your calculation is correct, then yes, sure (if it's > clear to the attacker what exact alphabet you used). > As I said, it's just counting. What do you mean by that, do you mean it doesn't say anything, it is just the relationship between these three things? If so, that's good enough for me, but then what does "password length" mean? If "sex", "love" and "god" are passwords of length 3, 4 and 3 respectively, I understand that, but what password length are we talking about when we are just counting? ;;; -*- lexical-binding: t -*- ;;; ;;; this file: ;;; https://dataswamp.org/~incal/emacs-init/epwgen.el ;;; ;;; 48 bits, alphabet length n, password length l ;;; 2^48 = n^l <=> ;;; 48*ln(2) = l*ln(n) <=> ;;; l = 48*ln(2)/ln(n) (defun epwgen-password-length (bits abc) (let ((abc-len (if (numberp abc) abc (when (listp abc) (length abc) )))) (when abc-len (/ (* bits (log 2)) (log abc-len)) ))) ;; (epwgen-password-length 48 60) ; 8.13 ;; (epwgen-password-length 48 '(a b c)) ; 30.28 (defun urandom (bits) (interactive "nbits: ") (let*((bytes (/ bits 8)) (bytes-opt (format "--bytes=%s" bytes)) ) (with-temp-buffer (set-buffer-multibyte nil) (call-process "head" "/dev/urandom" t nil bytes-opt) (string-to-list (buffer-substring-no-properties (point-min) (point-max)) )))) ;; (urandom 100) (provide 'epwgen) -- underground experts united https://dataswamp.org/~incal