Google Inc.

Giuseppe Persiano

Sarvar M Patel

Kevin Yeo

Mariana Raykova

Joon Young Seo

A method for providing response-hiding searchable encryption includes receiving a search query for a keyword from a user device associated with a user. The keyword appears in one or more encrypted documents within a corpus of encrypted documents stored on an untrusted storage device. The method also includes accessing a document oblivious key-value storage (OKVS) to obtain a list of document identifiers associated with the keyword. Each document identifier in the list of document identifiers associated with a respective keyword identifier is concatenated with the keyword and uniquely identifies a respective one of the one or more encrypted documents that the keyword appears in. The method also includes returning the list of document identifiers obtained from the document OKVS to the user device.

Response-hiding searchable encryption

A method includes initializing a client state on a client device be executing a private batched sum retrieval instruction to compute c sums O of data blocks from an untrusted storage device. Each computed sum O stored on memory hardware of the client device and including a sum of a corresponding subset S of exactly k data blocks. The method also includes a query instruction to retrieve a query block Bstored on the untrusted storage device by iterating through each of the c sums O of data blocks to identify one of the c sums O that does not include the query block B, instructing a service to pseudorandomly partition the untrusted storage device into partitions and sum the data blocks in each partition to determine a corresponding encrypted data block sum.

Private information retrieval with sublinear public-key operations

A method for sharing read access to a document stored on memory hardware. The method includes receiving a shared read access command from a sharor sharing read access to a sharee for a document stored on memory hardware in communication with the data processing hardware, and receiving a shared read access request from the sharee. The shared read access command includes an encrypted value and a first cryptographic share value based on a write key, a read key, a document identifier, and a sharee identifier. The method also includes multiplying the first and second cryptographic share values to determine a cryptographic read access value. The cryptographic read access value authorizes read access to the sharee for the document. The method also includes storing a read access token for the sharee including the cryptographic read access value and the encrypted value in a user read set of the memory hardware.

Encrypted search cloud service with cryptographic sharing

A method includes executing an instruction to execute a query for a data block, the data block associated with a corresponding memory level of a logarithmic number of memory levels (l) of memory, each memory level (l) including physical memory (RAM) residing on memory hardware of a distributed system. The method also includes retrieving a value associated with the data block from an oblivious hash table using a corresponding key, and extracting un-queried key value pairs from the oblivious hash table associated with un-queried data blocks after executing a threshold number of queries for data blocks. The method also includes a multi-array shuffle routine on the extracted key value pairs from the oblivious hash table to generate an output array containing the un-queried key value pairs.

Oblivious RAM with logarithmic overhead

A method executing an instruction () to execute a query (q) for a data block () and determining whether the data block is stored in a block stash (). When the data block is stored in the block stash during a download phase, the method includes removing the data block from the block stash, sending a fake query () to a distributed system () to retrieve a random data block stored in memory () of a distributed system (), and discarding the random data block. When a current version of the data block is stored in the block stash during an overwrite phase, the method includes sending a fake query to the distributed system to retrieve another random data block stored in the memory of the distributed system, decrypting and re-encrypting the random data block with fresh randomness, and re-uploading the re-encrypted random data block onto the distributed system.

Oblivious access with differential privacy

A method () includes initializing a client state () on a client device () be executing a private batched sum retrieval instruction () to compute c sums O of data blocks () from an untrusted storage device (). Each computed sum O stored on memory hardware () of the client device and including a sum of a corresponding subset S of exactly k data blocks. The method also includes a query instruction () to retrieve a query block Bstored on the untrusted storage device by iterating through each of the c sums O of data blocks to identify one of the c sums O that does not include the query block B, instructing a service to pseudorandomly partition the untrusted storage device into partitions and sum the data blocks in each partition to determine a corresponding encrypted data block sum ().

A method for performing encrypted search includes receiving a search query for a plurality of keywords from a user device that appear in one or more encrypted documents stored on an untrusted storage device. The method also includes accessing an encrypted search index to obtain a first list of document identifiers each representative of a document that includes a first keyword and a second keyword of the plurality of keywords. The method also includes, for each remaining keyword, determining a corresponding list of document identifiers each representative of a document that includes the first, second, and respective remaining keyword. The method includes determining, based on the first list of document identifiers and each corresponding list of document identifiers, a second list of document identifiers each representative of a document that includes each of the plurality of keywords. The method also includes returning the second list to the user device.

Growing community of inventors

New York, NY, United States of America

Giuseppe Persiano