On: Show HN: BeaconDB – An Alternative to Mozilla Loca...

[fc_on_hn]

> If my neighbour scans my WiFi network and uploads it to BeaconDB I didn’t exactly opt-in, did I?

To clarify: all phones doing geolocation are already uploading your AP macaddr to remote location services, but BeaconDB will *not* publish this information in cleartext.

Any data dump will contain only non-reversible cryptographically hashed data or aggregated data.

[kevincox → fc_on_hn]

A MAC address is only 48 bits and some of the bits are restricted. It is well within the range of brute force to reverse all of the hashes.

[joelkoen → kevincox]

You can truncate the hash to cause collisions, meaning that one MAC address does not map to one location. This requires the client to be aware of multiple physically nearby MACs in order to get a location, as it then needs to estimate which "possible" locations are most likely.

This is a really interesting problem, and I've loved thinking about it recently. If you're keen on it too I'm happy to discuss further, feel free to reach out.

[userbinator → kevincox]

To put that into perspective, 48 bits is 256T, which is roughly the number of bits in a 32TB hard drive.

[account42 → userbinator]

> and some of the bits are restricted

[landdownsundar → kevincox]

Absolutely right, great point. That's why I only use Windows addresses now. Can't break those with brute force!