Patent ID: 9465874
Filing Date: 2016-10-11
CPC Classification: G06F,H04L

Claim Text:
1. A method performed by a third party server for processing a query on a plurality of data sets, wherein said data sets are stored in a memory and outsourced from a source of said data sets, wherein said query comprises a hierarchical set operation between at least two of said data sets, said method comprising: obtaining, from said source, said data sets, corresponding encoded versions of said data sets, and a verification of said encoded versions; generating an answer to said query using said data sets, wherein at least one level of a hierarchy of said hierarchical set operation of said query comprises at least a first one of an intersection operation, a union operation and a set difference operation, and wherein at least a second level different from the first level of said hierarchy comprises at least a second distinct one of said intersection operation, said union operation and said set difference operation; parsing said query as a tree, wherein leaf nodes in said tree correspond to at least two of said data sets associated with said query and non-leaf nodes in said tree correspond to at least one of said intersection operation, said union operation and said set difference operation; for each leaf node in said tree corresponding to a given data set, computing a verification for an encoded version of said given data set that is based on said obtained encoded versions of said data sets and said obtained verification of said encoded versions; for each non-leaf node in said tree, computing at least one argument for a corresponding at least one of said intersection operation, said union operation and said set difference operation; and providing an encoded version of said answer and a proof-of-correctness to said client, wherein said proof-of-correctness comprises said computed verification for each leaf node encoding, and said at least one argument for each non-leaf node set operation, wherein said provided encoded version of said answer and said provided proof-of-correctness are used by said client to authenticate said hierarchical set operation.