Files
MP-SPDZ/Protocols/Share.h
Marcel Keller 4ef6b6d873 Maintenance.
2020-05-08 21:43:05 +10:00

251 lines
7.7 KiB
C++

#ifndef _Share
#define _Share
/* Class for holding a share of either a T or gfp element */
#include <vector>
#include <iostream>
using namespace std;
#include "Math/gf2n.h"
#include "Protocols/SPDZ.h"
#include "Protocols/SemiShare.h"
#include "ShareInterface.h"
// Forward declaration as apparently this is needed for friends in templates
template<class T> class Share;
template<class T> class MAC_Check_;
template<class T> class Direct_MAC_Check;
template<class T> class Passing_MAC_Check;
template<class T> class MascotMultiplier;
template<class T> class MascotFieldPrep;
template<class T> class MascotTripleGenerator;
template<class T> class MascotPrep;
union square128;
namespace GC
{
template<class T> class TinierSecret;
}
// abstracting SPDZ and SPDZ-wise
template<class T, class V>
class Share_ : public ShareInterface
{
T a; // The share
V mac; // Shares of the mac
public:
typedef V mac_key_type;
typedef V mac_type;
typedef T share_type;
typedef typename T::open_type open_type;
typedef typename T::clear clear;
typedef GC::TinierSecret<gf2n_short> bit_type;
const static bool needs_ot = T::needs_ot;
const static bool dishonest_majority = T::dishonest_majority;
const static bool variable_players = T::variable_players;
static int size()
{ return T::size() + V::size(); }
static string type_short()
{ return string(1, T::type_char()); }
static char type_char()
{ return T::type_char(); }
static DataFieldType field_type()
{ return T::field_type(); }
static int threshold(int nplayers)
{ return T::threshold(nplayers); }
static Share_ constant(const clear& aa, int my_num, const typename V::Scalar& alphai)
{ return Share_(aa, my_num, alphai); }
template<class U, class W>
void assign(const Share_<U, W>& S)
{ a=S.get_share(); mac=S.get_mac(); }
void assign(const char* buffer)
{ a.assign(buffer); mac.assign(buffer + T::size()); }
void assign_zero()
{ a.assign_zero();
mac.assign_zero();
}
void assign(const clear& aa, int my_num, const typename V::Scalar& alphai);
Share_() { assign_zero(); }
template<class U, class W>
Share_(const Share_<U, W>& S) { assign(S); }
Share_(const clear& aa, int my_num, const typename V::Scalar& alphai)
{ assign(aa, my_num, alphai); }
Share_(const T& share, const V& mac) : a(share), mac(mac) {}
const T& get_share() const { return a; }
const V& get_mac() const { return mac; }
void set_share(const T& aa) { a=aa; }
void set_mac(const V& aa) { mac=aa; }
/* Arithmetic Routines */
void mul(const Share_<T, V>& S,const clear& aa);
void mul_by_bit(const Share_<T, V>& S,const clear& aa);
void add(const Share_<T, V>& S,const clear& aa,int my_num,const V& alphai);
void negate() { a.negate(); mac.negate(); }
void sub(const Share_<T, V>& S,const clear& aa,int my_num,const V& alphai);
void sub(const clear& aa,const Share_<T, V>& S,int my_num,const V& alphai);
void add(const Share_<T, V>& S1,const Share_<T, V>& S2);
void sub(const Share_<T, V>& S1,const Share_<T, V>& S2);
void add(const Share_<T, V>& S1) { add(*this,S1); }
// obsolete interface
void add(const Share_<T, V>& S,const clear& aa,bool playerone,const T& alphai);
void sub(const Share_<T, V>& S,const clear& aa,bool playerone,const T& alphai);
void sub(const clear& aa,const Share_<T, V>& S,bool playerone,const T& alphai);
Share_<T, V> operator+(const Share_<T, V>& x) const
{ Share_<T, V> res; res.add(*this, x); return res; }
Share_<T, V> operator-(const Share_<T, V>& x) const
{ Share_<T, V> res; res.sub(*this, x); return res; }
template <class U>
Share_<T, V> operator*(const U& x) const
{ Share_<T, V> res; res.mul(*this, x); return res; }
Share_<T, V> operator/(const T& x) const
{ Share_<T, V> res; res.set_share(a / x); res.set_mac(mac / x); return res; }
Share_<T, V>& operator+=(const Share_<T, V>& x) { add(x); return *this; }
Share_<T, V>& operator-=(const Share_<T, V>& x) { sub(*this, x); return *this; }
template <class U>
Share_<T, V>& operator*=(const U& x) { mul(*this, x); return *this; }
Share_<T, V> operator<<(int i) { return this->operator*(T(1) << i); }
Share_<T, V>& operator<<=(int i) { return *this = *this << i; }
Share_<T, V> operator>>(int i) { return {a >> i, mac >> i}; }
void force_to_bit() { a.force_to_bit(); }
// Input and output from a stream
// - Can do in human or machine only format (later should be faster)
void output(ostream& s,bool human) const
{ a.output(s,human); if (human) { s << " "; }
mac.output(s,human);
}
void input(istream& s,bool human)
{ a.input(s,human);
mac.input(s,human);
}
friend ostream& operator<<(ostream& s, const Share_<T, V>& x) { x.output(s, true); return s; }
void pack(octetStream& os, bool full = true) const;
void unpack(octetStream& os, bool full = true);
};
// SPDZ(2k) only
template<class T>
class Share : public Share_<SemiShare<T>, SemiShare<T>>
{
public:
typedef Share_<SemiShare<T>, SemiShare<T>> super;
typedef T mac_key_type;
typedef Share<typename T::next> prep_type;
typedef Share input_check_type;
typedef Share input_type;
typedef MascotMultiplier<Share> Multiplier;
typedef MascotTripleGenerator<prep_type> TripleGenerator;
typedef T sacri_type;
typedef typename T::Square Rectangle;
typedef Rectangle Square;
typedef MAC_Check_<Share> MAC_Check;
typedef Passing_MAC_Check<Share> Direct_MC;
typedef ::Input<Share> Input;
typedef ::PrivateOutput<Share> PrivateOutput;
typedef SPDZ<Share> Protocol;
typedef MascotFieldPrep<Share> LivePrep;
typedef MascotPrep<Share> RandomPrep;
static const bool expensive = true;
static string type_string()
{ return "SPDZ " + T::type_string(); }
template<class U>
static void read_or_generate_mac_key(string directory, const Names& N,
U& key);
Share() {}
template<class U>
Share(const U& other) : super(other) {}
Share(const SemiShare<T>& share, const SemiShare<T>& mac) :
super(share, mac) {}
};
// specialized mul by bit for gf2n
template <>
void Share_<SemiShare<gf2n>, SemiShare<gf2n>>::mul_by_bit(const Share_<SemiShare<gf2n>, SemiShare<gf2n>>& S,const gf2n& aa);
template <class T, class V>
Share_<T, V> operator*(const typename T::clear& y, const Share_<T, V>& x) { Share_<T, V> res; res.mul(x, y); return res; }
template<class T, class V>
inline void Share_<T, V>::add(const Share_<T, V>& S1,const Share_<T, V>& S2)
{
a.add(S1.a,S2.a);
mac.add(S1.mac,S2.mac);
}
template<class T, class V>
void Share_<T, V>::sub(const Share_<T, V>& S1,const Share_<T, V>& S2)
{
a.sub(S1.a,S2.a);
mac.sub(S1.mac,S2.mac);
}
template<class T, class V>
inline void Share_<T, V>::mul(const Share_<T, V>& S,const clear& aa)
{
a.mul(S.a,aa);
mac = aa * S.mac;
}
template<class T, class V>
inline void Share_<T, V>::add(const Share_<T, V>& S,const clear& aa,int my_num,const V& alphai)
{
*this = S + Share_<T, V>(aa, my_num, alphai);
}
template<class T, class V>
inline void Share_<T, V>::sub(const Share_<T, V>& S,const clear& aa,int my_num,const V& alphai)
{
*this = S - Share_<T, V>(aa, my_num, alphai);
}
template<class T, class V>
inline void Share_<T, V>::sub(const clear& aa,const Share_<T, V>& S,int my_num,const V& alphai)
{
*this = Share_<T, V>(aa, my_num, alphai) - S;
}
template<class T, class V>
inline void Share_<T, V>::assign(const clear& aa, int my_num,
const typename V::Scalar& alphai)
{
a = T::constant(aa, my_num);
mac = aa * alphai;
#ifdef DEBUG_MAC
cout << "load " << hex << mac << " = " << aa << " * " << alphai << endl;
#endif
}
#endif