Consider access control/crypto features in the file format

[asdawn]

Our vector tiles contain several layers(tagged with an attribute called "layer"), we want to send necessary layers, not all of them. We want to find an efficient way.

We always treat vector tiles as open access basemap, the clients can cache and save the complete dataset. Sometimes we have to add access control over the datasets (for example role related sensitive data).

It is easy add a soft control, we can write a style function to show wanted contents. However it is not precise enough, because the complete dataset will still be send.

Split one vector tile to several vector tiles according to layer name, send only wanted layers is okay. But it will waste a lot of resources since at each grid we have to request more tiles. Resolve, filtrate then re-encode the tile on-the-fly will cost much and the increase the latency.

So, is it possible to add some index in the header part (or a independant index), let the server remove unwanted parts and concatenate the rest parts, or just fill zeros (the resolver have to ignore zero parts)?

Or, add some encrypt mechanism at the (so called) layer level?

I think this should be taken into consideration in the long run. Thanks.