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MP-SPDZ/GC/Secret.hpp

339 lines
9.0 KiB
C++

/*
* EvalSecret.cpp
*
*/
#include "Secret.h"
#include "Secret_inline.h"
namespace GC
{
template<class T>
Secret<T> Secret<T>::input(Processor<Secret<T>>& processor, const InputArgs& args)
{
return T::get_input(processor, args);
}
template<class T>
Secret<T> Secret<T>::input(party_id_t from, const int128& input, int n_bits)
{
Secret<T> res;
if (n_bits < 0)
n_bits = default_length;
#ifdef DEBUG_INPUT
cout << "input " << input << endl;
#endif
for (int i = 0; i < n_bits; i++)
{
res.get_new_reg().input(from, input.get_bit(i));
#ifdef DEBUG_INPUT
cout << (int)input.get_bit(i);
#endif
}
#ifdef DEBUG_INPUT
cout << " input" << endl;
#endif
if ((size_t)n_bits != res.registers.size())
{
cout << n_bits << " " << res.registers.size() << endl;
throw runtime_error("wrong bit length in input()");
}
#ifdef DEBUG_INPUT
for (auto& reg : res.registers)
cout << (int)reg.get_mask_no_check();
cout << " mask " << endl;
for (auto& reg : res.registers)
cout << (int)reg.get_external_no_check();
cout << " ext " << endl;
int128 a;
res.reveal(a);
cout << " input " << hex << a << "(" << res.size() << ") from " << from
<< " (" << input << ", " << dec << n_bits << ")" << endl;
#endif
return res;
}
template<class T>
void Secret<T>::random(int n_bits, int128 share)
{
(void)share;
if (n_bits > 128)
throw not_implemented();
#ifdef NO_INPUT
resize_regs(n_bits);
for (int i = 0; i < n_bits; i++)
get_reg(i).random();
#else
for (int i = 0; i < CommonParty::singleton->get_n_parties(); i++)
{
Secret<T> tmp = *this;
Secret<T> s = input(i + 1, share, n_bits);
*this = tmp + s;
#ifdef DEBUG_DYNAMIC
int128 a,b,c;
tmp.reveal(a);
s.reveal(b);
reveal(c);
cout << c << " = " << a << " ^ " << b << " (" << dec << n_bits << ", " << share << ")" << endl;
#endif
}
#endif
#ifdef DEBUG_RANDOM
int128 revealed;
reveal(revealed);
cout << "random " << revealed << " share " << share << endl;
#endif
if ((size_t)n_bits != registers.size())
{
cout << n_bits << " " << registers.size() << endl;
throw runtime_error("wrong bit length in random()");
}
}
template <class T>
void Secret<T>::random_bit()
{
#ifdef NO_INPUT
return random(1, 0);
#else
return random(1, CommonParty::s().prng.get_uchar() & 1);
#endif
}
template <class T>
template <class U, class V>
void Secret<T>::store(U& mem,
vector<WriteAccess<V> >& accesses)
{
T::store(mem, accesses);
}
template <class T>
void Secret<T>::output(T& reg)
{
cast(reg).output();
}
template <class T>
Secret<T> Secret<T>::carryless_mult(const Secret<T>& x, const Secret<T>& y)
{
Secret<T> res;
if (x.registers.size() == 0)
throw not_implemented();
#ifdef DEBUG_DYNAMIC2
for (int i = 0; i < x.registers.size(); i++)
output(x.registers[i]);
for (int i = 0; i < y.registers.size(); i++)
output(y.registers[i]);
#endif
for (size_t i = 0; i < x.registers.size() + y.registers.size() - 1; i++)
{
int start = max((size_t)0, i - y.registers.size() + 1);
int stop = min(i + 1, x.registers.size());
T sum = AND<T>(x.get_reg(start), y.get_reg(i - start));
#ifdef DEBUG_DYNAMIC2
output(sum);
cout << "carryless " << i << " " << start << " " << i - start <<
" sum " << (int)cast(sum).get_output() <<
" x " << (int)x.get_reg(start).get_output() <<
" y " << (int)y.get_reg(i - start).get_output() <<
" sum id " << sum.get_reg().get_id() << endl;
#endif
for (int j = start + 1; j < stop; j++)
{
T product = AND<T>(x.get_reg(j), y.get_reg(i - j));
sum = XOR<T>(sum, product);
#ifdef DEBUG_DYNAMIC2
cout << "carryless " <<
" prod id " << product.get_reg().get_id() <<
" sum id " << sum.get_reg().get_id() << endl << flush;
output(product);
output(sum);
cout << "carryless " << i << " " << j << " " << i - j <<
" prod " << (int)cast(product).get_output() <<
" sum " << (int)cast(sum).get_output() <<
" x " << (int)x.get_reg(j).get_output() <<
" y " << (int)y.get_reg(i - j).get_output() << endl;
#endif
}
res.registers.push_back(sum);
}
#ifdef DEBUG_DYNAMIC
word a, b;
int128 c;
x.reveal(a);
y.reveal(b);
res.reveal(c);
cout << typeid(T).name() << endl;
cout << c << " = " << hex << a << " * " << b << endl;
AuthValue d;
d.assign(a, b, false);
if (d.mac != c)
throw runtime_error("carryless mult");
#endif
return res;
}
template <class T>
Secret<T>::Secret()
{
}
template<class T>
T& GC::Secret<T>::get_new_reg()
{
registers.push_back(T::new_reg());
T &res = cast(registers.back());
#ifdef DEBUG_REGS
cout << "Secret: new " << typeid(T).name() << " " << res.get_id() << " at " << &res << endl;
#endif
return res;
}
template <class T>
void Secret<T>::load_clear(int n, const Integer& x)
{
if ((unsigned)n < 8 * sizeof(x) and abs(x.get()) > (1LL << n))
throw out_of_range("public value too long");
#ifdef DEBUG_ROUNDS2
cout << "secret from integer " << hex << this << dec << " " << endl;
#endif
resize_regs(n);
for (int i = 0; i < n; i++)
{
get_reg(i).public_input((x.get() >> i) & 1);
}
#ifdef DEBUG_VALUES
cout << "input " << x << endl;
for (int i = 0; i < n; i++)
cout << ((x.get() >> i) & 1);
cout << endl;
cout << "on registers: " << endl;
for (int i = 0; i < n; i++)
cout << get_reg(i).get_id() << " ";
cout << endl;
#endif
}
template <class T>
template <class U, class V>
void Secret<T>::load(vector<ReadAccess <V> >& accesses, const U& mem)
{
for (auto&& access : accesses)
{
int n = access.length;
if (n <= 0 || n > default_length)
throw runtime_error("invalid length for dynamic loading");
access.dest.resize_regs(n);
}
T::load(accesses, mem);
}
template <class T>
Secret<T> Secret<T>::operator<<(int i)
{
Secret<T> res;
for (int j = 0; j < i; j++)
res.get_new_reg().public_input(0);
res.registers.insert(res.registers.end(), registers.begin(),
registers.end());
return res;
}
template <class T>
Secret<T> Secret<T>::operator>>(int i)
{
Secret<T> res;
res.registers.insert(res.registers.end(), registers.begin() + i, registers.end());
return res;
}
template <class T>
template <class U>
void Secret<T>::bitcom(Memory<U>& S, const vector<int>& regs)
{
registers.clear();
for (unsigned int i = 0; i < regs.size(); i++)
{
if (S[regs[i]].registers.size() != 1)
throw Processor_Error("can only compose bits");
registers.push_back(S[regs[i]].registers.at(0));
}
}
template <class T>
template <class U>
void Secret<T>::bitdec(Memory<U>& S, const vector<int>& regs) const
{
if (regs.size() > registers.size())
throw out_of_range(
"not enough bits for bit decomposition: "
+ to_string(regs.size()) + " > "
+ to_string(registers.size()));
for (unsigned int i = 0; i < regs.size(); i++)
{
Secret& secret = S[regs[i]];
secret.registers.clear();
secret.registers.push_back(registers.at(i));
}
}
template<class T>
template<class U>
void Secret<T>::trans(Processor<U>& processor, int n_outputs,
const vector<int>& args)
{
int n_inputs = args.size() - n_outputs;
for (int i = 0; i < n_outputs; i++)
{
processor.S[args[i]].resize_regs(n_inputs);
for (int j = 0; j < n_inputs; j++)
processor.S[args[i]].registers[j] =
processor.S[args[n_outputs + j]].registers[i];
}
}
template <class T>
template <class U>
void Secret<T>::reveal(size_t n_bits, U& x)
{
#ifdef DEBUG_OUTPUT
cout << "revealing " << this << " with min(" << 8 * sizeof(U) << ","
<< registers.size() << ") bits" << endl;
#endif
if (n_bits > registers.size())
throw out_of_range("not enough wires for revealing");
x = 0;
for (unsigned int i = 0; i < min(8 * sizeof(U), registers.size()); i++)
{
get_reg(i).output();
char out = get_reg(i).get_output();
x ^= U(out) << i;
#ifdef DEBUG_OUTPUT
cout << (int)out;
#endif
}
#ifdef DEBUG_OUTPUT
cout << " output" << endl;
for (auto& reg : registers)
cout << (int)reg.get_mask_no_check();
cout << " mask" << endl;
for (auto& reg: registers)
cout << (int)reg.get_external_no_check();
cout << " ext" << endl;
#endif
#ifdef DEBUG_VALUES
cout << typeid(T).name() << " " << &x << endl;
cout << "reveal " << registers.size() << " bits: " << hex << showbase << x << dec << endl;
cout << "from registers:" << endl;
for (unsigned int i = 0; i < registers.size(); i++)
cout << registers[i].get_id() << " ";
cout << endl;
#endif
}
} /* namespace GC */