too long

Im trying to create a validation on both on create and update on the same field the problem is that everytime i execute it it always do both on create and update i would just like it to do on create when im saving a data and on update when im update a data on the same field on password

    'password' => array(
        'notEmpty' => array(
            'on' => 'update',
            'rule' => array('notEmpty', 'パスワード'),
            'allowEmpty' => true,
            'required' => false
        ),
        'notEmpty' => array(
            'on' => 'create',
            'rule' => array('notEmpty', 'パスワード'),
            'allowEmpty' => false,
            'required' => true
        ),
    ),

'password' => array(
    'notEmptyUpdate' => array(
        'on' => 'update',
        'rule' => array('notEmpty', 'パスワード'),
        'allowEmpty' => true,
        'required' => false
    ),
    'notEmptyCreate' => array(
        'on' => 'create',
        'rule' => array('notEmpty', 'パスワード'),
        'allowEmpty' => false,
        'required' => true
    ),
),