hej py

pir/pir_Supreme.py

@@ -0,0 +1,93 @@
+import random
+import math
+
+n = 8
+k = 3
+x = "11110101"
+
+
+
+
+def findS():
+	for s_candidate in range(k, n+1):
+		binom = math.factorial(s_candidate) / ( math.factorial(k-1) * (math.factorial(s_candidate - (k-1))) )
+		if binom >= n:
+			return s_candidate
+
+
+s = findS()
+
+
+def makeOneSeq(seq):
+	ones_remainding_counter = k - 1
+	while ones_remainding_counter != 0:
+		rand_idx = random.randint(0, s - 1)
+		if seq[rand_idx] == "0":
+			seq_temp = list(seq)
+			seq_temp[rand_idx] = "1"
+			seq = "".join(seq_temp)
+			ones_remainding_counter -= 1
+	return seq
+
+def makeSequences():
+	sequnces = [ "0"*s for j in range(n) ]
+	for i, seq in enumerate(sequnces):
+		candidate = makeOneSeq(seq)
+		while( candidate in sequnces):
+			candidate = makeOneSeq(seq)
+		sequnces[i] = candidate
+	sequnces.sort()
+	return sequnces
+
+
+sequnces = makeSequences()
+
+#print(sequnces)
+
+
+def user_send(rands, i):
+	gs = [[rands[l] * z + int(i[l]) for l in range(0, s)] for z in range(1, k+1)]
+	return gs
+
+
+def servers_comp(gs):
+	Fs = []
+	for g in gs:
+		F = 0
+		for j in range(0, n):
+			f = 1
+			j_bitstring = sequnces[j]
+			for l in range(s):
+				if int(j_bitstring[l]) == 1:
+					f *= g[l]
+			F += f * int(x[j])
+		Fs.append(F)
+	return Fs
+
+def poly_interpolation(x, Fs):
+	add_product = 0
+	for i in range(0, k):
+		mult_product = 1
+		for j in range(0, k):
+			if j != i:
+				mult_product *= (x - (j+1))/((i+1) - (j+1))
+		add_product += mult_product * Fs[i]
+	return int(add_product)
+
+
+def protocol(i):
+	rands = [random.randint(1,20) for r in range(s)]
+
+	gs = user_send(rands, i)
+	Fs = servers_comp(gs)
+	F0 = poly_interpolation(0, Fs)
+
+	# print(F0)
+
+	return F0
+
+
+for i in range(n):
+	i_bitstring = sequnces[i]
+	F0 = protocol(i_bitstring)
+	assert (F0 == int(x[i]))