address review

poc/flp_generic.py

@@ -843,9 +843,9 @@ def test_encode_truncate_decode(flp, measurements):
 
 
 def test_encode_truncate_decode_with_fft_fields(cls, measurements, *args):
-    for _field in [field.Field64, field.Field96, field.Field128]:
-        cls_with_field = cls.with_field(_field)
-        assert cls_with_field.Field == _field
+    for f in [field.Field64, field.Field96, field.Field128]:
+        cls_with_field = cls.with_field(f)
+        assert cls_with_field.Field == f
         obj = cls_with_field(*args)
         assert isinstance(obj, cls)
         test_encode_truncate_decode(FlpGeneric(obj), measurements)

poc/vdaf_prio3.py

@@ -7,7 +7,7 @@
 import xof
 from common import (ERR_INPUT, ERR_VERIFY, TEST_VECTOR, Unsigned, byte, concat,
                     front, vec_add, vec_sub, zeros)
-from field import FftField, Field64, Field96, Field128
+from field import FftField, Field64
 from vdaf import Vdaf, test_vdaf
 
 USAGE_MEAS_SHARE = 1
@@ -32,7 +32,7 @@ class Prio3(Vdaf):
     RAND_SIZE = None  # Computed from `Xof.SEED_SIZE` and `SHARES`
     ROUNDS = 1
     SHARES = None  # A number between `[2, 256)` set later
-    PROOFS = 1  # Number of proofs
+    PROOFS = 1  # Number of proofs, default to 1, otherwise see `Prio3SumVecWithMultiproof.is_recommended`
 
     # Types required by `Vdaf`
     Measurement = Flp.Measurement
@@ -520,24 +520,13 @@ class Prio3SumVecWithMultiproof(Prio3SumVec):
     def is_recommended(valid_cls,
                        num_proofs: Unsigned,
                        field: FftField) -> bool:
-        if num_proofs >= 0x100:
-            # We encode this as one byte while deriving joing rands
-            return False
-        # TODO(issue#177) Decide how many proofs to use for each field type.
+        # TODO(issue#177) Decide how many proofs to use.
         if field == Field64:
-            return num_proofs >= 2
-        elif field == Field96:
-            return num_proofs >= 2
-        elif field == Field128:
-            return num_proofs >= 1
+            # the upper bound is due to the fact
+            # we encode it using one byteb in `joint_rands`
+            return 2 <= num_proofs < 0x100
         return False
 
-    @staticmethod
-    def algorithm_id_from(num_proofs: Unsigned,
-                          field: FftField) -> Unsigned:
-        # To be confirmed
-        return 0xFFFFFFFF
-
     @classmethod
     def with_params(cls,
                     length: Unsigned,
@@ -549,10 +538,9 @@ def with_params(cls,
         if not cls.is_recommended(valid_cls, num_proofs, field):
             raise ValueError("parameters not recommended")
 
-        algorithm_id = cls.algorithm_id_from(num_proofs, field)
-
         class Prio3SumVecWithMultiproofAndParams(cls):
-            ID = algorithm_id
+            # Associated parameters.
+            ID = 0xFFFFFFFF
             PROOFS = num_proofs
             Flp = flp_generic.FlpGeneric(valid_cls(length, bits, chunk_length))
         return Prio3SumVecWithMultiproofAndParams
@@ -583,8 +571,8 @@ class TestPrio3AverageWithBits(TestPrio3Average):
 
 def _test_prio3sumvec(num_proofs: Unsigned, field: FftField):
     valid_cls = flp_generic.SumVec.with_field(field)
-    if not Prio3SumVecWithMultiproof.is_recommended(valid_cls, num_proofs, field):
-        return
+    assert Prio3SumVecWithMultiproof.is_recommended(
+        valid_cls, num_proofs, field)
 
     cls = Prio3SumVecWithMultiproof \
         .with_params(10, 8, 9, num_proofs=num_proofs, field=field) \
@@ -626,9 +614,8 @@ def _test_prio3sumvec(num_proofs: Unsigned, field: FftField):
 
 
 def test_prio3sumvec_with_multiproof():
-    for n in range(1, 5):
-        for f in [Field64, Field96, Field128]:
-            _test_prio3sumvec(num_proofs=n, field=f)
+    for n in range(2, 5):
+        _test_prio3sumvec(num_proofs=n, field=Field64)
 
 
 if __name__ == '__main__':