Source code for blind_transpiler.controllers.fdqc

from ..essentials.bqc_instruction import BQCInstruction
from ..essentials.bop import BOP
from .base import BaseController
from ..global_value_store import GlobalVariablesAndFunctions



class FDQC(BaseController):
    def __init__(self):
        BaseController.__init__(self)

        None


    def fdqc(self, trans_circ, keys):
        '''
        Convert the circuit in full-blind quantum computation circuit.

        Logic:
            iterate the circuit element by element
                check if element is client implementable
                    add instruction as op_type = 'client'
                if not 
                    used FDQC class to convert get the sequence of gates and store in list with order no.
        
        Args:
            trans_circ (QuantumCircuit):
                transpiled circuit in the basis set whose translation is present in translator library.

        Returns:
            bqc_instruction (list[BOP])
                list of BOP in order which they need to be implemented.
            
        '''
        GVF = GlobalVariablesAndFunctions()
        from ..translators.universalOrderedSetTranslator import UniversalOrderedSetTranslator
        # client_basis = self.client_basis 
        # server_basis = self.server_basis
        constant_compute_space = GVF.fdqc_compute_space

        bqc_instructions = BQCInstruction()   # is list of tuples (step, Op)
        bqc_instructions.n_qubits = trans_circ.num_qubits + constant_compute_space   # add extra qubits for server resource set
        bqc_instructions.n_cbits = trans_circ.count_ops().get('measure', 0)
        bqc_instructions.format = 'fdqc'

        translation_map = self._create_translation_map(UniversalOrderedSetTranslator(), format='fdqc')

        key_counter = 0

        for step, data in enumerate(trans_circ.data):
            instr = data.operation
            qargs = data.qubits
            cargs = data.clbits

            qargs = tuple([trans_circ.find_bit(q)[0] + constant_compute_space for q in qargs])   # extract index of qubit from QuantumRegister element
                                                                            # and update the qargs to adjust the server resource set padding
            cargs = tuple([trans_circ.find_bit(c)[0]  for c in cargs])   # as measure will not happen on resource set, no need to add the space

            if instr.name in self.client_basis:
                gate = instr.__class__(*instr.params) # takes out the name of class from the instr class
                if instr.name == 'measure':
                    secure_gate = BOP('measure', qargs, cargs, gate, gate_seq = step )
                else:
                    secure_gate = BOP('client', qargs, cargs, gate, gate_seq = step )
                bqc_instructions.add_elements(secure_gate)

            elif instr.name in self.server_basis:
                translation_func = translation_map[instr.name]
                gate_key_size = self.fdqc_key_map[instr.name]
                if instr.name == 'rz':   # as 'rz' gate take parameter theta
                    secure_gate = translation_func(instr.params[0], tuple(keys[key_counter: key_counter+gate_key_size]), qargs, gate_seq= step)
                else:
                    secure_gate = translation_func(tuple(keys[key_counter: key_counter+gate_key_size]), qargs, gate_seq= step)

                bqc_instructions.add_elements( [*secure_gate] )

                key_counter += gate_key_size

            elif instr.name in ['barrier']: #barrier does not effect only visual indication, update rules outside to include it in transpiled circuit
                from qiskit.circuit.library import Barrier
                secure_gate = BOP('barrier', qargs , cargs , Barrier(len(qargs)), gate_seq = step )
                continue

            elif instr.name in ['barrier']: # no need to do anything if gate is barrier
                continue
            else:
                raise KeyError(f'Gate {instr.name} not in any basis set.')
                
        return bqc_instructions