[curiouscats]

I am pretty sure there are smart locks that don't rely on an active connection to the cloud. The lock downloads keys when it has a connection and a smartphone can download keys. This means they work even if no active internet connection at the time the person tries to open. If the connection was dead the entire time between creating the new key and the person trying to use the lock it still wouldn't work.

If there are not locks that work this way it sure seems like there should be. Using cloud services to enable cool features is great. But if those services are not designed from the beginning with fallback for when the internet/cloud isn't live that is something that is a weakness that often is unwise to leave in place imo.

[andrewjshults]

FWIW - The Nest lock in question doesn't rely on an active internet connection to work. If it can't connect, it can still be unlocked using the sets of PINs you can setup for individual users (including setting start/end times and time of day that the codes are active). There's even a set of 9V battery terminals at the bottom in case you forget to change the batteries that power the lock.

This does mean you need to setup a code in advance of people showing up, but it's an under 30 second setup that I've found simpler than unlocking once someone shows up. The cameras dropping offline are a hot mess though, since those have no local storage option.

[dltmrcd]

It may not be worth the complexity to give users the choice. If I were to issue keys to guests this way I would want my revocations to be immediately effective no matter what. Guest keys requiring a working network is a fine trade-off.

[azernik]

You can have this without user intervention - have the lock download an expiration time with the list of allowed guest keys, or have the guest keys public-key signed with metadata like expiration time.

If the cloud is down, revocations aren't going to happen instantly anyway. (Although you might be able to hack up a local WiFi or Bluetooth fallback.)