Merge other basic circuits here

circuits/pointbits.circom

@@ -0,0 +1,144 @@
+include "bitify.circom";
+include "aliascheck.circom";
+include "compconstant.circom";
+include "babyjub.circom";
+
+
+function sqrt(n) {
+
+    if (n == 0) {
+        return 0;
+    }
+
+    // Test that have solution
+    var res = n ** ((-1) >> 1);
+//        if (res!=1) assert(false, "SQRT does not exists");
+    if (res!=1) return 0;
+
+    var m = 28;
+    var c = 19103219067921713944291392827692070036145651957329286315305642004821462161904;
+    var t = n ** 81540058820840996586704275553141814055101440848469862132140264610111;
+    var r = n ** ((81540058820840996586704275553141814055101440848469862132140264610111+1)>>1);
+    var sq;
+    var i;
+    var b;
+    var j;
+
+    while ((r != 0)&&(t != 1)) {
+        sq = t*t;
+        i = 1;
+        while (sq!=1) {
+            i++;
+            sq = sq*sq;
+        }
+
+        // b = c ^ m-i-1
+        b = c;
+        for (j=0; j< m-i-1; j ++) b = b*b;
+
+        m = i;
+        c = b*b;
+        t = t*c;
+        r = r*b;
+    }
+
+    if (r > ((-1) >> 1)) {
+        r = -r;
+    }
+
+    return r;
+}
+
+
+template Bits2Point() {
+    signal input in[256];
+    signal output out[2];
+}
+
+template Bits2Point_Strict() {
+    signal input in[256];
+    signal output out[2];
+
+    var i;
+
+    // Check aliasing
+    component aliasCheckY = AliasCheck();
+    for (i=0; i<254; i++) {
+        aliasCheckY.in[i] <== in[i];
+    }
+    in[254] === 0;
+
+    component b2nY = Bits2Num(254);
+    for (i=0; i<254; i++) {
+        b2nY.in[i] <== in[i];
+    }
+
+    out[1] <== b2nY.out;
+
+    var a = 168700;
+    var d = 168696;
+
+    var y2 = out[1] * out[1];
+
+    var x = sqrt(   (1-y2)/(a - d*y2)  );
+
+    if (in[255] == 1) x = -x;
+
+    out[0] <-- x;
+
+    component babyCheck = BabyCheck();
+    babyCheck.x <== out[0];
+    babyCheck.y <== out[1];
+
+    component n2bX = Num2Bits(254);
+    n2bX.in <== out[0];
+    component aliasCheckX = AliasCheck();
+    for (i=0; i<254; i++) {
+        aliasCheckX.in[i] <== n2bX.out[i];
+    }
+
+    component signCalc = CompConstant(10944121435919637611123202872628637544274182200208017171849102093287904247808);
+    for (i=0; i<254; i++) {
+        signCalc.in[i] <== n2bX.out[i];
+    }
+
+    signCalc.out === in[255];
+}
+
+
+template Point2Bits() {
+    signal input in[2];
+    signal output out[256];
+
+
+}
+
+template Point2Bits_Strict() {
+    signal input in[2];
+    signal output out[256];
+
+    var i;
+
+    component n2bX = Num2Bits(254);
+    n2bX.in <== in[0];
+    component n2bY = Num2Bits(254);
+    n2bY.in <== in[1];
+
+    component aliasCheckX = AliasCheck();
+    component aliasCheckY = AliasCheck();
+    for (i=0; i<254; i++) {
+        aliasCheckX.in[i] <== n2bX.out[i];
+        aliasCheckY.in[i] <== n2bY.out[i];
+    }
+
+    component signCalc = CompConstant(10944121435919637611123202872628637544274182200208017171849102093287904247808);
+    for (i=0; i<254; i++) {
+        signCalc.in[i] <== n2bX.out[i];
+    }
+
+    for (i=0; i<254; i++) {
+        out[i] <== n2bY.out[i];
+    }
+    out[254] <== 0;
+    out[255] <== signCalc.out;
+}