12. The computerized EDS server of claim 10 , wherein the computer processor; receives a pattern search query expression provided by a user.
12. The computerized EDS server of claim 10 , wherein the computer processor; receives a pattern search query expression provided by a user. 13. The computerized EDS server of claim 12 , wherein the EDS server then translates the query provided by the user by extracting a set of unique trigrams from the query expression; and using the set of unique trigrams to construct a covering-pattern-query on color tags that is issued to the cloud storage platform to search over encrypted documents stored in a portion of the cloud-storage platform associated with the user.