Big H2(ZZn6 y)
{ // Hash and compress an Fp6 to a big number
sha sh;
ZZn u,v,w;
ZZn2 x;
Big a,h,p,xx[2];
char s[HASH_LEN];
int i,j,m;
shs_init(&sh);
y.get(x);
x.get(u,v);
xx[0]=u; xx[1]=v;
for (i=0;i<2;i++)
{
a=xx[i];
while (a>0)
{
m=a%256;
shs_process(&sh,m);
a/=256;
}
}
shs_hash(&sh,s);
h=from_binary(HASH_LEN,s);
return h;
}
Big H2(ZZn6 x)
{ // Hash an Fp6 to a big number
sha256 sh;
ZZn2 u,v,w;
ZZn h,l;
Big a,hash,p,xx[6];
char s[HASH_LEN];
int i,j,m;
shs256_init(&sh);
x.get(u,v,w);
u.get(l,h);
xx[0]=l; xx[1]=h;
v.get(l,h);
xx[2]=l; xx[3]=h;
w.get(l,h);
xx[4]=l; xx[5]=h;
for (i=0;i<6;i++)
{
a=xx[i];
while (a>0)
{
m=a%256;
shs256_process(&sh,m);
a/=256;
}
}
shs256_hash(&sh,s);
hash=from_binary(HASH_LEN,s);
return hash;
}
Big H2(ZZn18 x)
{ // Compress and hash an Fp18 to a big number
sha256 sh;
ZZn6 u;
ZZn3 h,l;
Big a,hash;
ZZn xx[6];
char s[HASH_LEN];
int i,j,m;
shs256_init(&sh);
x.get(u); // compress to single ZZn6
u.get(l,h);
l.get(xx[0],xx[1],xx[2]);
h.get(xx[3],xx[4],xx[5]);
for (i=0;i<6;i++)
{
a=(Big)xx[i];
while (a>0)
{
m=a%256;
shs256_process(&sh,m);
a/=256;
}
}
shs256_hash(&sh,s);
hash=from_binary(HASH_LEN,s);
return hash;
}
void PFC::add_to_hash(const GT& x)
{
ZZn6 u;
ZZn18 v=x.g;
ZZn3 h,l;
Big a;
ZZn xx[6];
int i,j,m;
v.get(u);
u.get(l,h);
l.get(xx[0],xx[1],xx[2]);
h.get(xx[3],xx[4],xx[5]);
for (i=0;i<6;i++)
{
a=(Big)xx[i];
while (a>0)
{
m=a%256;
shs256_process(&SH,m);
a/=256;
}
}
}
void unshuffle(ZZn6 &S,ZZn3 &first,ZZn3 &second)
{ // unshuffle a ZZn6 into two ZZn3's
ZZn x0,x1,x2,x3,x4,x5;
ZZn2 t0,t1,t2;
S.get(t0,t1,t2);
t0.get(x0,x3);
t1.get(x1,x4);
t2.get(x2,x5);
first.set(x0,x2,x4);
second.set(x1,x3,x5);
}
Big H2(ZZn6 x)
{ // Hash an Fp6 to a big number
sha sh;
Big a,h,p,xx[6];
char s[20];
int i,j,m;
shs_init(&sh);
x.get(xx);
for (i=0;i<6;i++)
{
a=xx[i];
while (a>0)
{
m=a%256;
shs_process(&sh,m);
a/=256;
}
}
shs_hash(&sh,s);
h=from_binary(20,s);
return h;
}
