Stop player from opening door using redstone

[blissful bone]

Wondering if there's a way to stop doors from being activated with redstone. This is due to the fact that I'm trying to make a lockable-doors system, and an easy way to cheese the system to not require a key and to easily break into anyone's property would just be to use a redstone block or button.
If this seems unfeasible, then that's fine.

[upbeat sage]

on redstone change:
    if event-block is iron door:
        wait a tick
        turn off event-block