add parent to proofs

cryptarchia/cryptarchia.py

@@ -177,6 +177,7 @@ class LeaderProof:
     nullifier: Id
     evolved_commitment: Id
     slot: Slot
+    parent: Id
     # The produced proof
 
     @staticmethod
@@ -190,6 +191,9 @@ class LeaderProof:
             #Secret inputs
             coin: Coin,
             #membership witness to check that coin.commitment() is in eligible_notes
+
+            #This is not verified in the proof but solved with cryptographic signatures and conflict resolution
+            parent: Id
             ):
         #These verifications are normally done in the risc0 zk-proof:
         lottery_ticket = LEADER_VRF.vrf(coin, epoch_nonce, slot)
@@ -199,21 +203,20 @@ class LeaderProof:
         assert(coin.commitment() in eligible_notes)
         evolved_coin = coin.evolve()
 
-
-
-
         return LeaderProof( # TODO: generate the proof with risc0
             nullifier=coin_nullifier,
             evolved_commitment=evolved_coin.commitment(),
             slot=slot,
+            parent=parent,
         )
 
     def verify(self, slot: Slot,
                _epoch_nonce: Id,
                _threshold_0: int,
                _threshold_1: int,
-               _eligible_notes: set[Id],):
+               _eligible_notes: set[Id],
-        return slot == self.slot #TODO: and verification of the proof with risc0
+               parent: Id):
+        return slot == self.slot and parent == self.parent #TODO: add verification of the proof with risc0
 
 
 @dataclass
@@ -299,9 +302,6 @@ class LedgerState:
     # This nonce is used to derive the seed for the slot leader lottery.
     # It's updated at every block by hashing the previous nonce with the
     # leader proof's nullifier.
-    #
-    # NOTE that this does not prevent nonce grinding at the last slot
-    # when the nonce snapshot is taken
     nonce: Id = None
 
     # set of commitments
@@ -472,7 +472,7 @@ class Follower:
     ) -> bool:
         threshold_0, threshold_1 = lottery_threshold(self.config.active_slot_coeff, epoch_state.total_active_stake())
         return (
-            proof.verify(slot, epoch_state.nonce(), threshold_0, threshold_1, current_state.commitments_lead)  # verify slot leader proof
+            proof.verify(slot, current_state.nonce, threshold_0, threshold_1, current_state.commitments_lead, parent)  # verify slot leader proof
             # Membership verification is included in the proof verification along with the PoS lottery:
             #and (
             #    current_state.verify_eligible_to_lead(proof.commitment)
@@ -709,15 +709,15 @@ class Leader:
     coin: Coin
 
     def try_prove_slot_leader(
-        self, epoch: EpochState, slot: Slot, eligible_notes: set[Id]
+        self, total_stake: int, nonce: Id, slot: Slot, eligible_notes: set[Id], parent: Id
     ) -> LeaderProof | None:
-        if self._is_slot_leader(epoch, slot):
+        if self._is_slot_leader(total_stake, nonce, slot):
-            threshold_0, threshold_1 = lottery_threshold(self.config.active_slot_coeff, epoch.total_active_stake())
+            threshold_0, threshold_1 = lottery_threshold(self.config.active_slot_coeff, total_stake)
-            return LeaderProof.new(slot, epoch.nonce(), threshold_0, threshold_1, eligible_notes, self.coin)
+            return LeaderProof.new(slot, nonce, threshold_0, threshold_1, eligible_notes, self.coin, parent)
 
-    def _is_slot_leader(self, epoch: EpochState, slot: Slot):
+    def _is_slot_leader(self, total_stake: int, nonce: Id, slot: Slot):
-        threshold_0, threshold_1 = lottery_threshold(self.config.active_slot_coeff, epoch.total_active_stake())
+        threshold_0, threshold_1 = lottery_threshold(self.config.active_slot_coeff, total_stake)
-        r = LEADER_VRF.vrf(self.coin, epoch.nonce(), slot)
+        r = LEADER_VRF.vrf(self.coin, nonce, slot)
         return r < leader_winning_threshold(threshold_0, threshold_1, self.coin.value)
 
 

cryptarchia/test_common.py

@@ -27,7 +27,7 @@ class TestNode:
         parent = self.follower.tip_id()
         epoch_state = self.epoch_state(slot)
         # TODO: use the correct leader commitment set
-        if leader_proof := self.leader.try_prove_slot_leader(epoch_state, slot, {self.leader.coin.commitment()}):
+        if leader_proof := self.leader.try_prove_slot_leader(epoch_state.total_active_stake(), self.follower.tip_state().nonce, slot, {self.leader.coin.commitment()}, parent):
             orphans = self.follower.unimported_orphans(parent)
             self.leader.coin = self.leader.coin.evolve()
             return BlockHeader(
@@ -63,18 +63,20 @@ def mk_genesis_state(initial_stake_distribution: list[Coin]) -> LedgerState:
 
 
 def mk_block(
-    parent: Id, slot: int, coin: Coin, content=bytes(32), orphaned_proofs=[]
+    parent: Id, slot: int, coin: Coin, leader_commitments=[], content=bytes(32), orphaned_proofs=[]
 ) -> BlockHeader:
     assert len(parent) == 32
     from hashlib import sha256
 
+    if len(leader_commitments) == 0:
+        leader_commitments = [coin.commitment()]
     return BlockHeader(
         slot=Slot(slot),
         parent=parent,
         content_size=len(content),
         content_id=sha256(content).digest(),
         # TODO: use the correct leader commitment set
-        leader_proof=LeaderProof.new(Slot(slot), bytes(32), 2**256, 0, {coin.commitment()}, coin),
+        leader_proof=LeaderProof.new(Slot(slot), bytes(32), 2**256, 0, set(leader_commitments), coin, parent),
         orphaned_proofs=orphaned_proofs,
     )
 

cryptarchia/test_leader.py

@@ -42,8 +42,8 @@ class TestLeader(TestCase):
         # interval `p +- margin_of_error` with high probabiltiy
         leader_rate = (
             sum(
-                # TODO: use the correct leader commitment set
+                # TODO: use the correct leader commitment set and ledger nonce instead of epoch nonce
-                l.try_prove_slot_leader(epoch, Slot(slot), {coin.commitment()}) is not None
+                l.try_prove_slot_leader(epoch.total_active_stake(), epoch.nonce(), Slot(slot), {coin.commitment()}, bytes(32)) is not None
                 for slot in range(N)
             )
             / N

cryptarchia/test_ledger_state_update.py

@@ -286,4 +286,4 @@ class TestLedgerStateUpdate(TestCase):
         # is imported into the main chain
         follower.on_block(orphan)
         follower.on_block(block_0_1)
-        assert follower.tip() == block_0_1
+        assert follower.tip() == block_0_1