circomlib/circuits/bitify.circom
2018-12-11 17:25:21 +01:00

102 lines
2.1 KiB
Plaintext

/*
Copyright 2018 0KIMS association.
This file is part of circom (Zero Knowledge Circuit Compiler).
circom is a free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
circom is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU General Public License
along with circom. If not, see <https://www.gnu.org/licenses/>.
*/
include "comparators.circom";
include "aliascheck.circom";
template Num2Bits(n) {
signal input in;
signal output out[n];
var lc1=0;
for (var i = 0; i<n; i++) {
out[i] <-- (in >> i) & 1;
out[i] * (out[i] -1 ) === 0;
lc1 += out[i] * 2**i;
}
lc1 === in;
}
template Num2Bits_strict() {
signal input in;
signal output out[254];
component aliasCheck = AliasCheck();
component n2b = Num2Bits(254);
in ==> n2b.in;
for (var i=0; i<254; i++) {
n2b.out[i] ==> out[i];
n2b.out[i] ==> aliasCheck.in[i];
}
}
template Bits2Num(n) {
signal input in[n];
signal output out;
var lc1=0;
for (var i = 0; i<n; i++) {
lc1 += in[i] * 2**i;
}
lc1 ==> out;
}
template Bits2Num_strict() {
signal input in[n];
signal output out;
component aliasCheck = AliasCheck();
component b2n = Bits2Num(254);
for (var i=0; i<254; i++) {
in[i] ==> b2n.in[i];
in[i] ==> aliasCheck.in[i];
}
b2n.out ==> out;
}
template Num2BitsNeg(n) {
signal input in;
signal output out[n];
var lc1=0;
component isZero;
isZero = IsZero();
var neg = n == 0 ? 0 : 2**n - in;
for (var i = 0; i<n; i++) {
out[i] <-- (neg >> i) & 1;
out[i] * (out[i] -1 ) === 0;
lc1 += out[i] * 2**i;
}
in ==> isZero.in;
lc1 + isZero.out * 2**n === 2**n - in;
}