Made initial hash optional (None for new accounts) (#529)

* feat: optional initial hash for new accounts
fix: use `core::ops::Not` instead of `std::ops::Not`
fix: address review comments
refactor: rename function
docs: update changelog
tests: add checking proven transaction id for cases when account creation was involved

* refactor: move `init_account_hash` function back to `Account`

* fix: no-std build

* fix: address review comments

miden-lib/src/transaction/inputs.rs

@@ -26,7 +26,7 @@ impl ToTransactionKernelInputs for PreparedTransaction {
         let account = self.account();
         let stack_inputs = TransactionKernel::build_input_stack(
             account.id(),
-            account.proof_init_hash(),
+            account.init_hash(),
             self.input_notes().commitment(),
             self.block_header().hash(),
         );
@@ -43,7 +43,7 @@ impl ToTransactionKernelInputs for ExecutedTransaction {
         let account = self.initial_account();
         let stack_inputs = TransactionKernel::build_input_stack(
             account.id(),
-            account.proof_init_hash(),
+            account.init_hash(),
             self.input_notes().commitment(),
             self.block_header().hash(),
         );
@@ -61,7 +61,7 @@ impl ToTransactionKernelInputs for TransactionWitness {
 
         let stack_inputs = TransactionKernel::build_input_stack(
             account.id(),
-            account.proof_init_hash(),
+            account.init_hash(),
             self.input_notes().commitment(),
             self.block_header().hash(),
         );

miden-tx/src/prover/mod.rs

@@ -63,7 +63,7 @@ impl TransactionProver {
 
         let builder = ProvenTransactionBuilder::new(
             account_id,
-            tx_witness.account().proof_init_hash(),
+            tx_witness.account().init_hash(),
             tx_outputs.account.hash(),
             block_hash,
             proof,

miden-tx/src/tests.rs

@@ -358,11 +358,14 @@ fn prove_witness_and_verify() {
     let executed_transaction = executor
         .execute_transaction(account_id, block_ref, &note_ids, data_store.tx_args().clone())
         .unwrap();
+    let executed_transaction_id = executed_transaction.id();
 
     let proof_options = ProvingOptions::default();
     let prover = TransactionProver::new(proof_options);
     let proven_transaction = prover.prove_transaction(executed_transaction).unwrap();
 
+    assert_eq!(proven_transaction.id(), executed_transaction_id);
+
     let serialised_transaction = proven_transaction.to_bytes();
     let proven_transaction = ProvenTransaction::read_from_bytes(&serialised_transaction).unwrap();
 

miden-tx/tests/integration/main.rs

@@ -138,12 +138,15 @@ impl DataStore for MockDataStore {
 pub fn prove_and_verify_transaction(
     executed_transaction: ExecutedTransaction,
 ) -> Result<(), TransactionVerifierError> {
+    let executed_transaction_id = executed_transaction.id();
     // Prove the transaction
 
     let proof_options = ProvingOptions::default();
     let prover = TransactionProver::new(proof_options);
     let proven_transaction = prover.prove_transaction(executed_transaction).unwrap();
 
+    assert_eq!(proven_transaction.id(), executed_transaction_id);
+
     // Serialize & deserialize the ProvenTransaction
     let serialised_transaction = proven_transaction.to_bytes();
     let proven_transaction = ProvenTransaction::read_from_bytes(&serialised_transaction).unwrap();

objects/src/accounts/mod.rs

@@ -96,7 +96,7 @@ impl Account {
     /// against a new account, public input for the initial account state is set to [ZERO; 4] to
     /// distinguish new accounts from existing accounts. The actual hash of the initial account
     /// state (and the initial state itself), are provided to the VM via the advice provider.
-    pub fn proof_init_hash(&self) -> Digest {
+    pub fn init_hash(&self) -> Digest {
         if self.is_new() {
             Digest::default()
         } else {

objects/src/transaction/transaction_id.rs

@@ -89,7 +89,7 @@ impl From<&ExecutedTransaction> for TransactionId {
         let input_notes_hash = tx.input_notes().commitment();
         let output_notes_hash = tx.output_notes().commitment();
         Self::new(
-            tx.initial_account().proof_init_hash(),
+            tx.initial_account().init_hash(),
             tx.final_account().hash(),
             input_notes_hash,
             output_notes_hash,