Fix nested_cmux

virtualsecureplatform · Mar 25, 2024 · 6bfb9e2 · 6bfb9e2
1 parent 165c43f
commit 6bfb9e2
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Showing 4 changed files with 17 additions and 39 deletions.
diff --git a/include/params/concrete.hpp b/include/params/concrete.hpp
@@ -61,7 +61,7 @@ struct lvl2param {
     static constexpr std::uint32_t Bg = 1 << Bgbit;
     static constexpr ErrorDistribution errordist =
         ErrorDistribution::ModularGaussian;
-    static const inline double α = std::pow(2.0, -39);  // fresh noise
+    static const inline double α = std::pow(2.0, -38);  // fresh noise
     using T = uint64_t;                                 // Torus representation
     static constexpr T μ = 1ULL << 61;
     static constexpr uint32_t plain_modulus = 8;

diff --git a/include/trlwe.hpp b/include/trlwe.hpp
@@ -166,19 +166,23 @@ TRLWE<P> trlweSymIntEncrypt(const std::array<typename P::T, P::n> &p,
 }
 
 template <class P>
-std::array<bool, P::n> trlweSymDecrypt(const TRLWE<P> &c, const Key<P> &key)
+Polynomial<P> trlwePhase(const TRLWE<P> &c, const Key<P> &key)
 {
     Polynomial<P> phase = c[P::k];
     for (int k = 0; k < P::k; k++) {
         Polynomial<P> mulres;
         std::array<typename P::T, P::n> partkey;
         for (int i = 0; i < P::n; i++) partkey[i] = key[k * P::n + i];
         PolyMul<P>(mulres, c[k], partkey);
-        if constexpr (hasq<P>)
-            for (int i = 0; i < P::n; i++) phase[i] += P::q - mulres[i];
-        else
-            for (int i = 0; i < P::n; i++) phase[i] -= mulres[i];
+        for (int i = 0; i < P::n; i++) phase[i] -= mulres[i];
     }
+    return phase;
+}
+
+template <class P>
+std::array<bool, P::n> trlweSymDecrypt(const TRLWE<P> &c, const Key<P> &key)
+{
+    Polynomial<P> phase = trlwePhase<P>(c, key);
 
     std::array<bool, P::n> p;
     if constexpr (hasq<P>) {

diff --git a/test/nested_cmux.cpp b/test/nested_cmux.cpp
@@ -25,23 +25,10 @@ PolyLvl1 uint2weight(uint64_t n)
 TRLWELvl1 trivial_TRLWELvl1(const PolyLvl1 &src)
 {
     TRLWELvl1 ret = {};
-    ret[1] = src;
+    ret[TFHEpp::lvl1param::k] = src;
     return ret;
 }
 
-PolyLvl1 phase_of_TRLWELvl1(const TRLWELvl1 &src, const SecretKey &skey)
-{
-    PolyLvl1 as;
-
-    TFHEpp::Polynomial<TFHEpp::lvl1param> partkey;
-    for (int i = 0; i < TFHEpp::lvl1param::n; i++)
-        partkey[i] = skey.key.lvl1[0 * TFHEpp::lvl1param::n + i];
-    TFHEpp::PolyMul<Lvl1>(as, src[0], partkey);
-    PolyLvl1 phase = src[1];
-    for (size_t i = 0; i < Lvl1::n; i++) phase[i] -= as[i];
-    return phase;
-}
-
 void dump_histgram_of_phase_of_TRLWELvl1(std::ostream &os, const PolyLvl1 &src)
 {
     std::vector<size_t> hist(10, 0);
@@ -73,13 +60,13 @@ int main()
               c0 = trivial_TRLWELvl1(uint2weight(0));
     TRLWELvl1 res = c1;
     dump_histgram_of_phase_of_TRLWELvl1(std::cout,
-                                        phase_of_TRLWELvl1(res, skey));
+                                        TFHEpp::trlwePhase<TFHEpp::lvl1param>(res, skey.key.lvl1));
     for (size_t i = 0; i < N; i++) {
         TRLWELvl1 tmp = res;
         TFHEpp::CMUXFFT<Lvl1>(res, guard.at(i), tmp, c0);
     }
     dump_histgram_of_phase_of_TRLWELvl1(std::cout,
-                                        phase_of_TRLWELvl1(res, skey));
+                                        TFHEpp::trlwePhase<TFHEpp::lvl1param>(res, skey.key.lvl1));
 
     /*
     PolyLvl1 testvec1 = {}, testvec2 = {};

diff --git a/test/nested_cmux_from_cb.cpp b/test/nested_cmux_from_cb.cpp
@@ -25,23 +25,10 @@ PolyLvl1 uint2weight(uint64_t n)
 TRLWELvl1 trivial_TRLWELvl1(const PolyLvl1 &src)
 {
     TRLWELvl1 ret = {};
-    ret[1] = src;
+    ret[TFHEpp::lvl1param::k] = src;
     return ret;
 }
 
-PolyLvl1 phase_of_TRLWELvl1(const TRLWELvl1 &src, const SecretKey &skey)
-{
-    PolyLvl1 as;
-
-    TFHEpp::Polynomial<TFHEpp::lvl1param> partkey;
-    for (int i = 0; i < TFHEpp::lvl1param::n; i++)
-        partkey[i] = skey.key.lvl1[0 * TFHEpp::lvl1param::n + i];
-    TFHEpp::PolyMul<Lvl1>(as, src[0], partkey);
-    PolyLvl1 phase = src[1];
-    for (size_t i = 0; i < Lvl1::n; i++) phase[i] -= as[i];
-    return phase;
-}
-
 void dump_histgram_of_phase_of_TRLWELvl1(std::ostream &os, const PolyLvl1 &src)
 {
     std::vector<size_t> hist(10, 0);
@@ -57,7 +44,7 @@ void dump_histgram_of_phase_of_TRLWELvl1(std::ostream &os, const PolyLvl1 &src)
 
 int main()
 {
-    const size_t N = 500;
+    const size_t N = 10;
     std::cout << "N = " << N << std::endl;
 
     SecretKey skey;
@@ -80,13 +67,13 @@ int main()
               c0 = trivial_TRLWELvl1(uint2weight(0));
     TRLWELvl1 res = c1;
     dump_histgram_of_phase_of_TRLWELvl1(std::cout,
-                                        phase_of_TRLWELvl1(res, skey));
+                                        TFHEpp::trlwePhase<TFHEpp::lvl1param>(res, skey.key.lvl1));
     for (size_t i = 0; i < N; i++) {
         TRLWELvl1 tmp = res;
         TFHEpp::CMUXFFT<Lvl1>(res, guard.at(i), tmp, c0);
     }
     dump_histgram_of_phase_of_TRLWELvl1(std::cout,
-                                        phase_of_TRLWELvl1(res, skey));
+                                        TFHEpp::trlwePhase<TFHEpp::lvl1param>(res, skey.key.lvl1));
 
     /*
     PolyLvl1 testvec1 = {}, testvec2 = {};