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nd: fixes

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This commit is contained in:
Mirek Kratochvil 2012-06-02 11:55:58 +02:00
parent c9df69a83f
commit 8bba17f754
3 changed files with 23 additions and 14 deletions
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6
include/codecrypt.h
View file

@ -70,7 +70,7 @@ public:
}
matrix operator* (const matrix&);
void mult (const matrix&);
void mult (const matrix&); //right multiply - this*param
void compute_transpose (matrix&);
bool compute_inversion (matrix&);
@ -246,10 +246,10 @@ public:
int prepare();
uint cipher_size() {
return Pinv.size();
return Sinv.size();
}
uint plain_size() {
return Sinv.width();
return Pinv.size();
}
uint plain_weight() {
return g.degree();

4
lib/mce.cpp
View file

@ -146,8 +146,8 @@ int privkey::sign (const bvector&in, bvector&out, uint delta, uint attempts, prn
if (syndrome_decode (synd, fld, g, sqInv, e2, true) ) {
//create the decodable message
p.add(e);
p.add(e2);
p.add (e);
p.add (e2);
hperm.permute (p, e2); //back to systematic
e2.resize (signature_size() ); //strip checks

27
lib/nd.cpp
View file

@ -23,18 +23,27 @@ int nd::generate (pubkey&pub, privkey&priv, prng&rng, uint m, uint t)
S.compute_inversion (priv.Sinv);
//permutation
permutation P;
P.generate_random (h.width(), rng);
P.compute_inversion (priv.Pinv);
priv.Pinv.generate_random (h.width(), rng);
/*
* note: we actually don't need the inversion, as it inverts itself
* when permuting SH to pubkey.
*/
//pubkey
pub.t = t;
S.mult (h);
P.permute (S, pub.H);
priv.Pinv.permute (S, pub.H);
return 0;
}
int privkey::prepare ()
{
g.compute_square_root_matrix (sqInv, fld);
return 0;
}
int pubkey::encrypt (const bvector& in, bvector&out)
{
if (in.size() != plain_size() ) return 1;
@ -64,22 +73,22 @@ int privkey::sign (const bvector&in, bvector&out, uint delta, uint attempts, prn
{
uint i, s, t;
bvector synd_orig, synd, e;
bvector synd_unsc, synd, e;
s = hash_size();
if (in.size() != s) return 2;
Sinv.mult_vec_right (in, synd_orig);
for (t = 0; t < attempts; ++t) {
synd = synd_orig;
synd = in;
for (i = 0; i < delta; ++i) {
uint pos = rng.random (s);
synd[pos] = !synd[pos]; //flip a bit
}
if (syndrome_decode (synd, fld, g, sqInv, e, true) ) {
Sinv.mult_vec_right (synd, synd_unsc);
if (syndrome_decode (synd_unsc, fld, g, sqInv, e, true) ) {
Pinv.permute (e, out);
return 0;