Modern geographic databases can contain a large volume of data that need to be distributed to subscribed customers. The data can be modeled as a cube, where typical dimensions include latitude, longitude, and time. One way of distributing the data consists of making freely available encrypted versions of selected subsets of the data, and giving each paying customer the decryption keys for their authorized subsets only. The total space for these encrypted versions should be close to linear in the size of the data, yet the subset for a customer can be an arbitrary orthogonal range of the data; there is a quadratic number of such subsets, and we do not know ahead of time which subset will be subscribed (so the almost linear, and a priori selected subsets, must be enough to exactly express any of the quadratic number of ranges that could possibly interest a customer). This is mainly a data structuring and algorithmic problem. For a geo-spatial database in which the geography is modeled as...
Hao Yuan, Mikhail J. Atallah