zkvm: remove import/export instructions (#296)

* zkvm: remove import/export instructions

* remove import/export log entries

* bump ci

zkvm/docs/zkvm-spec.md

@@ -546,8 +546,6 @@ following instructions:
 * [`issue`](#issue)
 * [`retire`](#retire)
 * [`log`](#log)
-* [`import`](#import)
-* [`export`](#export)
 
 See the specification of each instruction for the details of which data is stored.
 
@@ -623,23 +621,6 @@ Data entry is added using [`log`](#log) instruction.
 T.commit("data", data)
 ```
 
-#### Import entry
-
-Import entry is added using [`import`](#import) instruction.
-
-```
-T.commit("import", proof)
-```
-
-#### Export entry
-
-Export entry is added using [`export`](#export) instruction.
-
-```
-T.commit("export", metadata)
-```
-
-
 
 ### Merkle binary tree
 
@@ -927,17 +908,15 @@ Code | Instruction                | Stack diagram                              |
 0x15 | [`borrow`](#borrow)        |         _qty flv_ → _–V +V_                | Modifies [CS](#constraint-system)
 0x16 | [`retire`](#retire)        |           _value_ → ø                      | Modifies [CS](#constraint-system), [tx log](#transaction-log)
 0x17 | [`cloak:m:n`](#cloak)      | _widevalues commitments_ → _values_        | Modifies [CS](#constraint-system)
-0x18 | [`import`](#import)        |   _proof qty flv_ → _value_                | Modifies [CS](#constraint-system), [tx log](#transaction-log), [defers point ops](#deferred-point-operations)
-0x19 | [`export`](#export)        |       _value ???_ → ø                      | Modifies [CS](#constraint-system), [tx log](#transaction-log)
  |                                |                                            |
  |     [**Contracts**](#contract-instructions)        |                        |
-0x1a | [`input`](#input)          |      _prevoutput_ → _contract_             | Modifies [tx log](#transaction-log)
-0x1b | [`output:k`](#output)      |   _items... pred_ → ø                      | Modifies [tx log](#transaction-log)
-0x1c | [`contract:k`](#contract)  |   _items... pred_ → _contract_             | 
-0x1d | [`log`](#log)              |            _data_ → ø                      | Modifies [tx log](#transaction-log)
-0x1e | [`signtx`](#signtx)        |        _contract_ → _results..._           | Modifies [deferred verification keys](#transaction-signature)
-0x1f | [`call`](#call)            |_contract(P) proof prog_ → _results..._     | [Defers point operations](#deferred-point-operations)
-0x20 | [`delegate`](#delegate)    |_contract prog sig_ → _results..._          | [Defers point operations](#deferred-point-operations)
+0x18 | [`input`](#input)          |      _prevoutput_ → _contract_             | Modifies [tx log](#transaction-log)
+0x19 | [`output:k`](#output)      |   _items... pred_ → ø                      | Modifies [tx log](#transaction-log)
+0x1a | [`contract:k`](#contract)  |   _items... pred_ → _contract_             | 
+0x1b | [`log`](#log)              |            _data_ → ø                      | Modifies [tx log](#transaction-log)
+0x1c | [`signtx`](#signtx)        |        _contract_ → _results..._           | Modifies [deferred verification keys](#transaction-signature)
+0x1d | [`call`](#call)            |_contract(P) proof prog_ → _results..._     | [Defers point operations](#deferred-point-operations)
+0x1e | [`delegate`](#delegate)    |_contract prog sig_ → _results..._          | [Defers point operations](#deferred-point-operations)
   —  | [`ext`](#ext)              |                 ø → ø                      | Fails if [extension flag](#vm-state) is not set.
 
 
@@ -1290,71 +1269,6 @@ Merges and splits `m` [wide values](#wide-value-type) into `n` [values](#value-t
 Immediate data `m` and `n` are encoded as two [LE32](#le32)s.
 
 
-#### import
-
-_proof qty flv_ **import** → _value_
-
-1. Pops [variable](#variable-type) `flv` and commits it to the constraint system.
-2. Pops [variable](#variable-type) `qty` and commits it to the constraint system.
-3. Pops [data](#data-type) `proof`.
-4. Creates a [value](#value-type) with variables `qty` and `flv` for quantity and flavor, respectively. 
-5. Computes the _flavor_ scalar defined by the [predicate](#predicate) `pred` using the following [transcript-based](#transcript) protocol:
-    ```
-    T = Transcript("ZkVM.import")
-    T.commit("extflavor", proof.external_flavor_id)
-    T.commit("extaccount", proof.pegging_account_id)
-    flavor = T.challenge_scalar("flavor")
-    ```
-6. Checks that the `flv` has unblinded commitment to `flavor` by [deferring the point operation](#deferred-point-operations):
-    ```
-    flv == flavor·B
-    ```
-7. Checks that the `qty` has unblinded commitment to `quantity` by [deferring the point operation](#deferred-point-operations):
-    ```
-    qty == proof.quantity·B
-    ```
-8. Adds an [import entry](#import-entry) with `proof` to the [transaction log](#transaction-log).
-9. Pushes the imported value to the stack.
-
-Note: the `proof` data contains necessary metadata to check if the value is pegged on the external blockchain.
-It is verified when the transaction is applied to the blockchain state.
-
-TBD: definition of the proof data (quantity, asset id, pegging account, identifier of the pegging transaction)
-
-Fails if:
-* `flv` or `qty` are not [variable types](#variable-type),
-* `proof` is not a [data type](#data-type).
-
-
-
-#### export
-
-_metadata value_ **export** → ø
-
-1. Pops [value](#value-type).
-2. Pops [data](#data-type) `metadata`.
-3. Computes the local flavor based on the pegging metadata:
-    ```
-    T = Transcript("ZkVM.import")
-    T.commit("extflavor", metadata.external_flavor_id)
-    T.commit("extaccount", metadata.pegging_account_id)
-    flavor = T.challenge_scalar("flavor")
-    ```
-4. Adds two constraints to the constraint system using cleartext quantity and flavor in the metadata:
-    ```
-    value.qty == metadata.qty
-    value.flv == flavor
-    ```
-5. Adds an [export entry](#export-entry) with `metadata` to the [transaction log](#transaction-log).
-
-TBD: definition of the metadata data (quantity, asset id, pegging account, target address/accountid)
-
-Fails if:
-* `value` is not a [non-negative value type](#value-type),
-* `metadata` is not a [data type](#data-type).
-
-
-
 ### Contract instructions
 
 
@@ -1878,4 +1792,4 @@ Also, instead of placing bounds on some received value, we now normally use `bor
 Thus, neither of these use cases requires `qty` and `flavor`.
 
 ### Open questions
-None at the moment.
+None at the moment.

zkvm/src/ops.rs

@@ -37,8 +37,6 @@ pub enum Instruction {
     Borrow,
     Retire,
     Cloak(usize, usize), // M inputs, N outputs
-    Import,
-    Export,
     Input,
     Output(usize),   // payload count
     Contract(usize), // payload count
@@ -78,18 +76,16 @@ pub enum Opcode {
     Borrow = 0x15,
     Retire = 0x16,
     Cloak = 0x17,
-    Import = 0x18,
-    Export = 0x19,
-    Input = 0x1a,
-    Output = 0x1b,
-    Contract = 0x1c,
-    Log = 0x1d,
-    Signtx = 0x1e,
-    Call = 0x1f,
+    Input = 0x18,
+    Output = 0x19,
+    Contract = 0x1a,
+    Log = 0x1b,
+    Signtx = 0x1c,
+    Call = 0x1d,
     Delegate = MAX_OPCODE,
 }
 
-const MAX_OPCODE: u8 = 0x20;
+const MAX_OPCODE: u8 = 0x1e;
 
 impl Opcode {
     /// Converts the opcode to `u8`.
@@ -184,8 +180,6 @@ impl Instruction {
                 let n = program.read_size()?;
                 Ok(Instruction::Cloak(m, n))
             }
-            Opcode::Import => Ok(Instruction::Import),
-            Opcode::Export => Ok(Instruction::Export),
             Opcode::Input => Ok(Instruction::Input),
             Opcode::Output => {
                 let k = program.read_size()?;
@@ -249,8 +243,6 @@ impl Instruction {
                 encoding::write_u32(*m as u32, program);
                 encoding::write_u32(*n as u32, program);
             }
-            Instruction::Import => write(Opcode::Import),
-            Instruction::Export => write(Opcode::Export),
             Instruction::Input => write(Opcode::Input),
             Instruction::Output(k) => {
                 write(Opcode::Output);

zkvm/src/program.rs

@@ -60,9 +60,7 @@ impl Program {
     def_op!(drop, Drop);
     def_op!(dup, Dup, usize);
     def_op!(eq, Eq);
-    def_op!(export, Export);
     def_op!(expr, Expr);
-    def_op!(import, Import);
     def_op!(input, Input);
     def_op!(issue, Issue);
     def_op!(log, Log);

zkvm/src/tx.rs

@@ -29,8 +29,6 @@ pub enum TxEntry {
     Input(ContractID),
     Output(Contract),
     Data(Vec<u8>),
-    Import, // TBD: parameters
-    Export, // TBD: parameters
 }
 
 /// Header metadata for the transaction
@@ -249,14 +247,6 @@ impl MerkleItem for TxEntry {
             TxEntry::Data(data) => {
                 t.commit_bytes(b"data", data);
             }
-            TxEntry::Import => {
-                // TBD: commit parameters
-                unimplemented!()
-            }
-            TxEntry::Export => {
-                // TBD: commit parameters
-                unimplemented!()
-            }
         }
     }
 }

zkvm/src/vm.rs

@@ -166,8 +166,6 @@ where
                 Instruction::Borrow => self.borrow()?,
                 Instruction::Retire => self.retire()?,
                 Instruction::Cloak(m, n) => self.cloak(m, n)?,
-                Instruction::Import => unimplemented!(),
-                Instruction::Export => unimplemented!(),
                 Instruction::Input => self.input()?,
                 Instruction::Output(k) => self.output(k)?,
                 Instruction::Contract(k) => self.contract(k)?,