int pubkey::encrypt (const bvector&in, bvector&out, const bvector&errors)
{
if (in.size() != plain_size() ) return 2;
if (errors.size() != cipher_size() ) return 2;
G.mult_vecT_left (in, out);
out.add (errors);
return 0;
}
int pubkey::encrypt (const bvector & in, bvector & out, const bvector&errors)
{
uint t = 1 << T;
bvector p, g, r, cksum;
uint i, j;
/*
* shortened checksum pair of G is computed blockwise accordingly to
* the t-sized square dyadic blocks.
*/
//some checks
if (!qd_sigs.width() ) return 1;
if (qd_sigs.height() % t) return 1;
if (in.size() != plain_size() ) return 2;
if (errors.size() != cipher_size() ) return 2;
uint blocks = qd_sigs.height() / t;
cksum.resize (qd_sigs.height(), 0);
p.resize (t);
g.resize (t);
r.resize (t);
std::vector<int> c1, c2, c3;
c1.resize (t);
c2.resize (t);
c3.resize (t);
for (i = 0; i < qd_sigs.size(); ++i) {
//plaintext block
in.get_block (i * t, t, p);
for (j = 0; j < blocks; ++j) {
//checksum block
qd_sigs[i].get_block (j * t, t, g);
//block result
fwht_dyadic_multiply (p, g, r, c1, c2, c3);
cksum.add_offset (r, t * j);
}
}
//compute ciphertext
out = in;
out.insert (out.end(), cksum.begin(), cksum.end() );
out.add (errors);
return 0;
}