From 5e4e14fb6196883fca6f77dd4e9b553f44e28092 Mon Sep 17 00:00:00 2001
From: Morten Dahl <mortendahlcs@gmail.com>
Date: Tue, 16 Jul 2019 22:55:59 +0200
Subject: [PATCH 1/2] first step of more elaborate Paillier example

---
 examples/paillier.py | 76 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 60 insertions(+), 16 deletions(-)

diff --git a/examples/paillier.py b/examples/paillier.py
index 2af05f9..c39f4ec 100644
--- a/examples/paillier.py
+++ b/examples/paillier.py
@@ -1,26 +1,70 @@
+import numpy as np
 import tensorflow as tf
 import tf_big
 
+# use secure operations by default
 tf_big.set_secure_default(True)
 
-p = tf_big.constant([17])
-q = tf_big.constant([19])
-n = p * q
+class EncryptionKey:
+  def __init__(self, n, nn, g):
+    self.n = n
+    self.nn = nn
+    self.g = g
 
-g = n + 1
-nn = n * n
+class DecryptionKey:
+  def __init__(self):
+    # TODO what do we need?
 
-x = tf.constant([[4]])
-# r = tf_big.random.uniform(n)
-r = tf_big.constant([82])
-assert r.shape == x.shape, (r.shape, x.shape)
+def keygen(modulus_bitlen):
+  # TODO
+  p = tf_big.constant(SOME PRIME)
+  q = tf_big.constant(SOME PRIME)
+  n = p * q
 
-gx = tf_big.pow(g, x, nn, secure=True)
-assert gx.shape.as_list() == [1, 1], gx.shape
-rn = tf_big.pow(r, n, nn, secure=True)
-assert rn.shape.as_list() == [1, 1], rn.shape
-c = gx * rn #% nn
+  g = n + 1
+  nn = n * n
+
+  ek = EncryptionKey(n, nn, g)
+  dk = DecryptionKey()
+  return ek, dk
+
+def encrypt(ek, x):
+  r = tf_big.random.uniform(ek.n, shape=x.shape)
+  assert r.shape == x.shape, "Shapes are not matching: {}, {}".format(r.shape, x.shape)
+
+  gx = tf_big.pow(ek.g, x, ek.nn)
+  rn = tf_big.pow(r, ek.n, ek.nn)
+  c = gx * rn % ek.nn
+  return c
+
+def decrypt(dk, c):
+  # TODO what do we need?
+
+def add(ek, c1, c2):
+  c = c1 * c2 % ek.nn
+  return c
+
+def mul(ek, c1, x2):
+  c = tf_big.pow(c1, x2, ek.nn)
+  return c
+
+ek, dk = keygen(2048)
+
+# TODO(Morten) relace with lin reg computation?
+
+x1 = tf.constant([[1, 2], [3, 4]])
+c1 = encrypt(ek, x1)
+
+x1 = tf.constant([[5, 6], [7, 8]])
+c2 = encrypt(ek, x2)
+
+c3 = add(ek, c1, c2)
+
+c4 = mul(ek, c3, tf.constant(3))
+
+y = decrypt(dk, c4)
 
 with tf.Session() as sess:
-  res = sess.run(c)
-  print(res)
+  actual = sess.run(tf_big.convert_from_tensor(y))
+  expected = (x1 + x2) * 3
+  np.testing.assert_array_equal(actual, expected)

From a35d6555dbcfde030af0b1dd5255bc4a81db7725 Mon Sep 17 00:00:00 2001
From: Morten Dahl <mortendahlcs@gmail.com>
Date: Mon, 26 Aug 2019 18:02:33 +0200
Subject: [PATCH 2/2] Update paillier.py

---
 examples/paillier.py | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/examples/paillier.py b/examples/paillier.py
index c39f4ec..93d55cb 100644
--- a/examples/paillier.py
+++ b/examples/paillier.py
@@ -14,11 +14,12 @@ def __init__(self, n, nn, g):
 class DecryptionKey:
   def __init__(self):
     # TODO what do we need?
+    pass
 
-def keygen(modulus_bitlen):
-  # TODO
-  p = tf_big.constant(SOME PRIME)
-  q = tf_big.constant(SOME PRIME)
+def dummy_keygen():
+  # TODO use fixed large primes  
+  p = tf_big.constant([17])
+  q = tf_big.constant([19])
   n = p * q
 
   g = n + 1
@@ -29,7 +30,8 @@ def keygen(modulus_bitlen):
   return ek, dk
 
 def encrypt(ek, x):
-  r = tf_big.random.uniform(ek.n, shape=x.shape)
+  # r = tf_big.random.uniform(ek.n, shape=x.shape)
+  r = tf_big.convert_to_tensor(tf.constant([[123, 124], [125, 126]])) # TODO
   assert r.shape == x.shape, "Shapes are not matching: {}, {}".format(r.shape, x.shape)
 
   gx = tf_big.pow(ek.g, x, ek.nn)
@@ -39,6 +41,7 @@ def encrypt(ek, x):
 
 def decrypt(dk, c):
   # TODO what do we need?
+  pass
 
 def add(ek, c1, c2):
   c = c1 * c2 % ek.nn
@@ -48,7 +51,7 @@ def mul(ek, c1, x2):
   c = tf_big.pow(c1, x2, ek.nn)
   return c
 
-ek, dk = keygen(2048)
+ek, dk = dummy_keygen()
 
 # TODO(Morten) relace with lin reg computation?
 
@@ -65,6 +68,6 @@ def mul(ek, c1, x2):
 y = decrypt(dk, c4)
 
 with tf.Session() as sess:
-  actual = sess.run(tf_big.convert_from_tensor(y))
+  actual = sess.run(y)
   expected = (x1 + x2) * 3
   np.testing.assert_array_equal(actual, expected)