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Merge pull request #59 from kryptnostic/fix/RxRyImplementation
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Random Rx, Ry
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@geekbeast
geekbeast committed Apr 28, 2016
2 parents 5eb30a0 + 4802701 commit 80c17fb
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Showing 2 changed files with 42 additions and 28 deletions.
57 changes: 40 additions & 17 deletions krypto-lib/src/main/cpp/BridgeKey.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,8 +30,6 @@ class BridgeKey{
BridgeKey(const PrivateKey<N> &pk) :
_pk(pk),
_R(BitMatrix<N>::randomInvertibleMatrix()),
_Rx(BitMatrix<N>::randomInvertibleMatrix()),
_Ry(BitMatrix<N>::randomInvertibleMatrix()),
_M(pk.getM()),
_Cu1(pk.getUnaryObf1()),
_Cu2(pk.getUnaryObf2()),
Expand All @@ -40,8 +38,6 @@ class BridgeKey{
_Ai(pk.getA().inv()),
_Bi(pk.getB().inv()),
_ARAi(pk.getA() * _R * _Ai),
_ARxAi(pk.getA() * _Rx * _Ai),
_ARyAi(pk.getA() * _Ry * _Ai),
_AiM2(_Ai.template pMult<2*N, 2*N>(_M.inv(), N))
{}

Expand Down Expand Up @@ -190,24 +186,30 @@ class BridgeKey{
return aug.template rMult<3*N>(_Cb2);
}


/* XOR */
struct H_XOR {
BitMatrix<2*N> _Xx, _Xy;
BitMatrix<2*N, 3*N> _Y;
void initialize(const BitMatrix<2*N> & Xx, const BitMatrix<2*N> & Xy, const BitMatrix<2*N, 3*N> & Y){
MultiQuadTuple<4*N, 3*N> _gb1;
MultiQuadTuple<3*N, 3*N> _gb2;
void initialize(const BitMatrix<2*N> & Xx, const BitMatrix<2*N> & Xy, const BitMatrix<2*N, 3*N> & Y, const MultiQuadTuple<4*N, 3*N> & gb1, const MultiQuadTuple<3*N, 3*N> & gb2){
_Xx = Xx;
_Xy = Xy;
_Y = Y;
_gb1 = gb1;
_gb2 = gb2;
}
const BitVector<2*N> operator()(const BitVector<2*N> &x, const BitVector<2*N> &y, const BitVector<3*N> & t) const{
const BitVector<2*N> operator()(const BitVector<2*N> &x, const BitVector<2*N> &y) const{
const BitVector<4*N> & concatXY = BitVector<4*N>::template vCat<2*N, 2*N>(x, y);
const BitVector<3*N> & t = _gb2(_gb1(concatXY));
return (_Xx * x) ^ (_Xy * y) ^ (_Y * t);
}
};

const H_XOR getXOR() const{
H_XOR result;
result.initialize(getXORXx(), getXORXy(), getXORY());
refreshParam();
result.initialize(getXORXx(), getXORXy(), getXORY(), getBinaryG1(), getBinaryG2());
return result;
}

Expand All @@ -217,34 +219,39 @@ class BridgeKey{
BitMatrix<2*N, 3*N> _MY3;
MultiQuadTuple<7*N, N> _z;
BitMatrix<2*N> _Z1, _Z2;
void initialize(const BitMatrix<2*N, N> & MB, const BitMatrix<2*N, 3*N> & MY3,
const MultiQuadTuple<7*N, N> & z,
const BitMatrix<2*N> & Z1, const BitMatrix<2*N> & Z2){
MultiQuadTuple<4*N, 3*N> _gb1;
MultiQuadTuple<3*N, 3*N> _gb2;
void initialize(const BitMatrix<2*N, N> & MB, const BitMatrix<2*N, 3*N> & MY3, const MultiQuadTuple<7*N, N> & z, const BitMatrix<2*N> & Z1, const BitMatrix<2*N> & Z2, const MultiQuadTuple<4*N, 3*N> & gb1, const MultiQuadTuple<3*N, 3*N> & gb2){
_MB = MB;
_MY3 = MY3;
_z = z;
_Z1 = Z1;
_Z2 = Z2;
_gb1 = gb1;
_gb2 = gb2;
}
const BitVector<2*N> operator()(const BitVector<2*N> &x, const BitVector<2*N> &y, const BitVector<3*N> & t) const{
const BitVector<2*N> operator()(const BitVector<2*N> &x, const BitVector<2*N> &y) const{
const BitVector<4*N> & concatXY = BitVector<4*N>::template vCat<2*N, 2*N>(x, y);
const BitVector<3*N> & t = _gb2(_gb1(concatXY));
const BitVector<7*N> & coordinates = BitVector<7*N>::vCat(x, y, t);
return (_MB * _z(coordinates)) ^ (_MY3 * t) ^ (_Z1 * x) ^ (_Z2 * y);
}
};

const H_AND getAND() const{
H_AND result;
refreshParam();
const BitMatrix<2*N, N> & MB = _M.template pMult(_pk.getB(), 0, 0, N);
const BitMatrix<2*N, 3*N> & MY3 = _M * BitMatrix<2*N, 3*N>::augV(_Cb2.inv().splitV3(2), BitMatrix<N, 3*N>::zeroMatrix());
result.initialize(MB, MY3, getANDz(), getANDZ1(), getANDZ2());
result.initialize(MB, MY3, getANDz(), getANDZ1(), getANDZ2(), getBinaryG1(), getBinaryG2());
return result;
}

private:
const PrivateKey<N> _pk;
const BitMatrix<N> _R;
const BitMatrix<N> _Rx;
const BitMatrix<N> _Ry;
BitMatrix<N> _Rx;
BitMatrix<N> _Ry;
const BitMatrix<2*N> _M;
const BitMatrix<2*N> _Cu1;
const BitMatrix<2*N> _Cu2;
Expand All @@ -253,12 +260,28 @@ class BridgeKey{
const BitMatrix<N> _Ai;
const BitMatrix<N> _Bi;
const BitMatrix<N> _ARAi;
const BitMatrix<N> _ARxAi;
const BitMatrix<N> _ARyAi;
BitMatrix<N> _ARxAi;
BitMatrix<N> _ARyAi;
const BitMatrix<N, 2*N> _AiM2;
static const unsigned int twoN = N << 1;
static const unsigned int threeN = 3 * N;

/*
* Function: Refresh and re-randomise Rx, Ry and all associated variables
* Returns void
*/
void refreshParam() {
// re-randomise Rx, Ry
_Rx.copy(BitMatrix<N>::randomInvertibleMatrix());
_Ry.copy(BitMatrix<N>::randomInvertibleMatrix());

// carry out all necessary modifications
const BitMatrix<N> & conjugateRx = _pk.getA() * _Rx * _Ai;
const BitMatrix<N> & conjugateRy = _pk.getA() * _Ry * _Ai;
_ARxAi.copy(conjugateRx);
_ARyAi.copy(conjugateRy);
}

/* Helper Functions for getXOR */

/*
Expand Down
13 changes: 2 additions & 11 deletions krypto-lib/src/main/cpp/PublicKey.h
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Original file line number Diff line number Diff line change
Expand Up @@ -26,8 +26,6 @@ class PublicKey{
_lc(bk.getLeftColumnMatrix()),
_gu1(bk.getUnaryG1()),
_gu2(bk.getUnaryG2()),
_gb1(bk.getBinaryG1()),
_gb2(bk.getBinaryG2()),
_XOR(bk.getXOR()),
_AND(bk.getAND())
{
Expand All @@ -38,11 +36,11 @@ class PublicKey{
}

const BitVector<2*N> homomorphicXOR(const BitVector<2*N> &x, const BitVector<2*N> &y) const{
return _XOR(x, y, binaryT(x, y));
return _XOR(x, y);
}

const BitVector<2*N> homomorphicAND(const BitVector<2*N> &x, const BitVector<2*N> &y) const{
return _AND(x, y, binaryT(x, y));
return _AND(x, y);
}

//single left shift (if the leftmost bit of x is nonzero, it'll be zeroed)
Expand Down Expand Up @@ -88,15 +86,8 @@ class PublicKey{
const BitMatrix<2*N, 4*N> _lc;
const MultiQuadTuple<2*N, 2*N> _gu1;
const MultiQuadTuple<2*N, 2*N> _gu2;
const MultiQuadTuple<4*N, 3*N> _gb1;
const MultiQuadTuple<3*N, 3*N> _gb2;
const typename BridgeKey<N>::H_XOR _XOR;
const typename BridgeKey<N>::H_AND _AND;

const BitVector<3*N> binaryT(const BitVector<2*N> &x, const BitVector<2*N> &y) const{
const BitVector<4*N> & concatXY = BitVector<4*N>::template vCat<2*N, 2*N>(x, y);
return _gb2(_gb1(concatXY));
}
};

#endif

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