def signature_verify(self,<EOL>message,<EOL>signature,<EOL>unique_identifier=None,<EOL>cryptographic_parameters=None,<EOL>credential=None):
operation = Operation(OperationEnum.SIGNATURE_VERIFY)<EOL>request_payload = payloads.SignatureVerifyRequestPayload(<EOL>unique_identifier=unique_identifier,<EOL>cryptographic_parameters=cryptographic_parameters,<EOL>data=message,<EOL>signature_data=signature<EOL>)<EOL>batch_item = messages.RequestBatchItem(<EOL>operation=operation,<EOL>request_payload=request_payload<EOL>)<EOL>request = self._build_request_message(credential, [batch_item])<EOL>response = self._send_and_receive_message(request)<EOL>batch_item = response.batch_items[<NUM_LIT:0>]<EOL>payload = batch_item.response_payload<EOL>result = {}<EOL>if payload:<EOL><INDENT>result['<STR_LIT>'] = payload.unique_identifier<EOL>result['<STR_LIT>'] = payload.validity_indicator<EOL><DEDENT>result['<STR_LIT>'] = batch_item.result_status.value<EOL>try:<EOL><INDENT>result['<STR_LIT>'] = batch_item.result_reason.value<EOL><DEDENT>except Exception:<EOL><INDENT>result['<STR_LIT>'] = batch_item.result_reason<EOL><DEDENT>try:<EOL><INDENT>result['<STR_LIT>'] = batch_item.result_message.value<EOL><DEDENT>except Exception:<EOL><INDENT>result['<STR_LIT>'] = batch_item.result_message<EOL><DEDENT>return result<EOL>
Verify a message signature using the specified signing key.

Args:
    message (bytes): The bytes of the signed message. Required.
    signature (bytes): The bytes of the message signature. Required.
    unique_identifier (string): The unique ID of the signing key to
        use. Optional, defaults to None.
    cryptographic_parameters (CryptographicParameters): A structure
        containing various cryptographic settings to be used for
        signature verification. Optional, defaults to None.
    credential (Credential): A credential object containing a set of
        authorization parameters for the operation. Optional, defaults
        to None.

Returns:
    dict: The results of the signature verify operation, containing the
        following key/value pairs:

        Key                  | Value
        ---------------------|-----------------------------------------
        'unique_identifier'  | (string) The unique ID of the signing
                             | key used to verify the signature.
        'validity_indicator' | (ValidityIndicator) An enumeration
                             | indicating the result of signature
                             | verification.
        'result_status'      | (ResultStatus) An enumeration indicating
                             | the status of the operation result.
        'result_reason'      | (ResultReason) An enumeration providing
                             | context for the result status.
        'result_message'     | (string) A message providing additional
                             | context for the operation result.