3 * $Id: sac.c,v 1.2 2000/07/02 15:21:20 mdw Exp $
5 * Testing for strict avalanche
7 * (c) 2000 Mark Wooding
10 /*----- Licensing notice --------------------------------------------------*
12 * Copyright (c) 2000 Mark Wooding
13 * All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions are
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
22 * 2, Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * 3. The name of the authors may not be used to endorse or promote
27 * products derived from this software without specific prior written
30 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
31 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
32 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
33 * NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
34 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
35 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
36 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
38 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
39 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
40 * POSSIBILITY OF SUCH DAMAGE.
42 * Instead of accepting the above terms, you may redistribute and/or modify
43 * this software under the terms of either the GNU General Public License,
44 * or the GNU Library General Public License, published by the Free
45 * Software Foundation; either version 2 of the License, or (at your
46 * option) any later version.
49 /*----- Revision history --------------------------------------------------*
52 * Revision 1.2 2000/07/02 15:21:20 mdw
55 * Revision 1.1 2000/05/21 11:28:30 mdw
60 /*----- Header files ------------------------------------------------------*/
70 #include "storin-tab.h"
72 /*----- Static variables --------------------------------------------------*/
76 /*----- The constant matrix -----------------------------------------------*/
78 static const uint24 m[] = STORIN_M;
80 /*----- Magic numbers -----------------------------------------------------*/
84 #define ROT(x) ((x) ^ ((x) >> 12))
85 /* #define ROT(x) ROL24(x, 7) */
87 /*----- Main code ---------------------------------------------------------*/
91 #define HAMWEIGHT(x) (w[U8((x) >> 16)] + w[U8((x) >> 8)] + w[U8(x)])
93 static void haminit(void) {
95 for (i = 0; i < 256; i++) {
98 for (j = 0; j < 8; j++) {
106 static void eblk(uint24 *x)
111 for (i = 0; i < ROUNDS; i++) {
113 matmul(t, m, x, 4, 4, 1);
114 for (j = 0; j < 4; j++)
119 typedef struct stats {
125 static void probe(unsigned bit, uint24 *delta, struct stats *ps)
129 struct stats s = { 0, 0, 0 };
131 for (i = 0; i < PROBES; i++) {
133 for (j = 0; j < 4; j++) {
134 x[j] = U24(fibrand_step(&r));
135 y[j] = x[j] ^ delta[j];
140 for (j = 0; j < 4; j++) {
141 uint24 ww = x[j] ^ y[j];
144 /* printf("%06x %06x %06x %06x -> %06x %06x %06x %06x\n", */
145 /* delta[0], delta[1], delta[2], delta[3], */
146 /* x[0] ^ y[0], x[1] ^ y[1], x[2] ^ y[2], x[3] ^ y[3]); */
147 s.sx += h; ps->sx += h;
148 s.sx2 += h * h; ps->sx2 += h * h;
153 double mean = s.sx / s.n;
154 double var = s.sx2 / s.n - mean * mean;
155 printf("bit %u: mean = %g, sd = %g\n", bit, mean, sqrt(var));
161 uint24 delta[4] = { 0 };
163 struct stats s = { 0, 0, 0 };
167 fibrand_lcseed(&r, 0);
169 for (i = 0; i < 96; i++) {
170 uint24 *dd = delta + i / 24;
171 uint24 m = 1 << (i % 24);
178 var = s.sx2 / s.n - mean * mean;
179 printf("\nsummary: mean = %g, sd = %g\n", mean, sqrt(var));
184 /*----- That's all, folks -------------------------------------------------*/