摘要 |
A method and an apparatus for matching elements within sets of trajectories, locations or other attributes without revealing the entire sets. The elements are partitioned into segments. A rotating selection is made among the sets and one segment of each potentially matching element is newly disclosed from the selected set. Optionally, the sets are cryptographically hashed, using, for example, a MD5 hash or a SHA-1 hash. Optionally, the sets are represented as tries, and successively lower levels within the tries are newly disclosed from potentially matching elements as the disclosing set rotates. Optionally, the sets are encoded, using: a grid of longitude and latitude; a spatial temporal grid; a overlapping spatial grid; a temporal grid; a set of cities; a set of countries; a set of names of places; or a set of attributes. Optionally, the matching process is repeated while refining the encoding. Optionally, negotiations determine what encoding or cryptographic hash is used.
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