International Business Machines Corporation

Hugo M Krawczyk

Jason K Resch

Tal D Rabin

Mark Duane Seaborn

Ashish Jagmohan

Demijan Klinc

Camit Hazay

Charanjit Singh Jutla

Marcel Catalin Rosu

Michael Steiner

Shay Kutten

Amir Herzberg

Charles D Cash

Stanislaw Jarecki

Frederic J Bauchot

Martin L Schmatz

David Frederick Bantz

Patricia Maria Sagmeister

Rosario Gennaro

Yishay Mansour

Eliane D Bello

Ashish Kundu

Dakshi Agrawal

Nataraj Nagaratnam

Suresh N Chari

Marcel Mordechay Yung

William Eric Hall

Chatschik Bisdikian

Kenneth Alan Goldman

Peter Anthony Sandon

Shai Halevi

Timothy Roy Block

Supriyo Chakraborty

Murtaza Zafer

Elaine Rivette Palmer

Kapil Kumar Singh

Christopher John Engel

Akshar Kaul

David Dean Sanner

Alwood Patrick Williams, Iii

Firas Bouz

Dong Su

Erlander Lo

Terry Dwain Escamilla

Hasini Gunasinghe

Stanislaw M Jarecki

Cagatay Capar

A method (and structure and computer product) to encrypt plaintext data into ciphertext data includes encrypting, using a processor on a computer, plaintext into corresponding ciphertext, using a Property Preserving Encryption (PPE) protocol in which a predefined property is maintained when plaintext values are encrypted into ciphertext values. The predefined property is randomly flipped during encryption to reverse the predefined property in the corresponding ciphertext node. An indication of whether the predefined property has been maintained or reversed is stored as the state of encryption.

Computing range queries over encrypted data

A method and computer system for implementing authentication protocol for merging multiple server nodes with trusted platform modules (TPMs) utilizing provisioned node certificates to support concurrent node add and node remove. Each of the multiple server nodes boots an instance of enablement level firmware and extended to a trusted platform module (TPM) on each node as the server nodes are powered up. A hardware secure channel is established between the server nodes for firmware message passing as part of physical configuration of the server nodes to be merged. A shared secret is securely exchanged via the hardware secure channel between the server nodes establishing an initial authentication value shared among all server nodes. All server nodes confirm common security configuration settings and exchange TPM log and platform configuration register (PCR) data to establish common history for future attestation requirements, enabling dynamic changing the server nodes and concurrently adding and removing nodes.

Implementing authentication protocol for merging multiple server nodes with trusted platform modules utilizing provisioned node certificates to support concurrent node add and remove

A computing device implements a key management system (KMS), and includes an interface, memory, and processing circuitry that executes operational instructions to maintain structured key parameters and a generating procedure associated with associated with a structured key. The generating procedure produces the structured key from an Oblivious Pseudorandom Function (OPRF) output, and the structured key parameters. The computing device receives a blinded value associated with the structured key from a requesting computing device, processes the blinded value using an OPRF secret to generate a blinded OPRF output, and returns the blinded OPRF output, the generating procedure, and the structured key parameters to the requesting computing device, which uses that information to generate the requested structured key.

Assymetric structured key recovering using oblivious pseudorandom function

A computing device including a processor, memory, and instructions, interfaces with a key management system (KMS) that provides encryption keys using an Oblivious Pseudorandom Function (OPRF). The device obtains, based on a type of encryption key being requested, a public key of a public-private key pair. The device creates an Oblivious Key Access Request (OKAR), including a blinded value associated with a requested encryption key. The OKAR is transmitted to the KMS, and a response is received. The response includes a blinded OPRF output, which yields an OPRF output as a result of being subjected to an unblinding operation. The OPRF output is validated using the public key, either directly or via a challenge, and in response to a positive validation, the OPRF output is used as a final key, or an intermediary key used to derive the final key.

Validating keys derived from an oblivious pseudorandom function

A computing device includes an interface configured to interface and communicate with a communication system, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory that is configured to execute the operational instructions to perform various operations. The computing device generates a sub-key identifier based on a data ID, which is based on unique ID value(s) associated with an encrypted data object, and a requester secret. The computing device processes the sub-key identifier in accordance with an Oblivious Pseudorandom Function (OPRF) blinding operation to generate a blinded input and an Oblivious Key Access Request (OKAR). The computing device transmits the OKAR to another computing device (e.g., Key Management System (KMS) service) and receives a blinded sub-key therefrom. The computing device processes the blinded sub-key in accordance with an OPRF unblinding operation to generate the key and accesses secure data thereby.

Key identifiers in an obliviousness pseudorandom function (OPRF)-based key management service (KMS)

A computing device includes an interface configured to interface and communicate with a communication system, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory that is configured to execute the operational instructions to perform various operations. The computing device processes an input value (e.g., associated with a key) based on a blinding key (e.g., homomorphic encryption) to generate a blinded value and generates an Oblivious Key Access Request (OKAR). The computing device transmits the OKAR to another computing device (e.g., associated with a Key Management System (KMS) service) and receives a blinded key therefrom that is based on a Partially-Oblivious Pseudorandom Function (P-OPRF). The computing device processes the blinded key based on the blinding key (e.g., homomorphic decryption) to generate the key (e.g., associated with the input value). In some examples, the computing device accesses secure information based on the key.

Virtualizing a key hierarchy using a partially-oblivious pseudorandom function (P-OPRF)

A computing device includes an interface configured to interface and communicate with a communication system, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory that is configured to execute the operational instructions to perform various operations. The computing device processes an input value associated with a key based on a blinding key in accordance with an Oblivious Pseudorandom Function (OPRF) blinding operation to generate a blinded value and transmits it to another computing device (e.g., that is associated with a Key Management System (KMS) service). The computing device then receives a blinded key that is based on processing of the blinded value based on an OPRF using an OPRF secret. The computing device processes the blinded key based on the blinding key in accordance with the OPRF unblinding operation to generate the key (e.g., to be used for secure information access).

Oblivious pseudorandom function in a key management system

A computing device is configured to divide an Oblivious Pseudorandom Function (OPRF) key to generate a plurality of N partial keys, distribute a respective one of the plurality of N partial keys to a corresponding plurality of N Key Management System (KMS) units. The computing device receives from a threshold number T of KMS units, a plurality T partial blinded keys, wherein the plurality T partial blinded keys are based on processing of a value of a blinded key received by a respective KMS unit and a corresponding stored partial key of the N partial keys, combines the plurality T of partial blinded keys into the blinded key, processes the blinded key based on the blinding key in accordance with an OPRF unblinding operation to generate a key and accesses secure information based on the key.

Threshold oblivious pseudorandom function in a key management system

A processor-implemented method improves security in a blockchain network of devices by protecting security, privacy and ownership assurance of identity assets, where the blockchain network of devices supports a blockchain. An identity asset provider device establishes co-ownership of an identity asset for an identity asset provider and an entity. The identity asset provider device directs a first member of the blockchain network of devices to associate identities of the identity asset provider and the entity based on their co-ownership of the identity asset by using commitments between the identity asset provider and the entity and based on collaborative proof of ownership of the identity asset using zero knowledge proofs in the blockchain network of devices.

Protection of confidentiality, privacy and ownership assurance in a blockchain based decentralized identity management system

A computing device includes an interface configured to interface and communicate with a communication system, a memory that stores operational instructions, and processing circuitry operably coupled to the interface and to the memory that is configured to execute the operational instructions to perform various operations. The computing device processes an input value in accordance with a Threshold Partially-Oblivious Pseudorandom Function (TP-OPRF) blinding operation to generate a blinded input. The computing device then selects a threshold number of shareholder computing devices that are associated with a Key Management System (KMS) service and transmits the blinded input to them. The computing device then receives at least a threshold number of blinded output components from at least some of the shareholder computing devices and processes them to generate a blinded output. The computing device then processes the blinded output in accordance with a TP-OPRF unblinding operation to generate a key.

Efficient computation of a threshold partially-oblivious pseudorandom function

A method for searching in an encrypted database includes the following steps. A search is formulated as a conjunct of two or more atomic search queries. One of the conjuncts is selected as a primary atomic search query. Search capabilities are generated for a secondary atomic search query using the primary atomic search query and the secondary atomic search query.

Masking query data access pattern in encrypted data

A method comprises receiving a first cryptographic token for one search term and a second cryptographic token is generated using the one search term and at least another search term. A first search is conducted using the first cryptographic token to generate a first result set, and the second cryptographic token is used for computing a subset of results of the first result set.

Conjunctive search in encrypted data

A method, system and computer program product are disclosed for compressing encrypted data, wherein the data is encrypted by using a block encryption algorithm in a chained mode of operation, and the encrypted data is comprised of a set of N encrypted blocks, C. . . C. In one embodiment, the method comprises leaving block Cuncompressed, and compressing all of the blocks C. . . Cin a defined sequence using a Slepian-Wolf code. In an embodiment, the data is encrypted using an encryption key K, and the compressing includes compressing all of the blocks C. . . Cwithout using the encryption key. In one embodiment, the compressing includes outputting the blocks C. . . Cas a set of compressed blocks CmprC. . . CmprC, and the method further comprises decrypting Cto generate a reconstructed block {tilde over (X)}, and decrypting and decompressing the set of compressed blocks using {tilde over (X)}.

Compressing encrypted data without the encryption key

A method for encrypting a database includes the following step. Keywords in the database are encrypted to obtain encrypted search tags for the keywords. A table of reverse indices is generated for the encrypted search tags. A table of cross keyword indices is generated. A method for searching in an encrypted database includes the following steps. A search is formulated as a conjunct of two or more atomic search queries. One of the conjuncts is selected as a primary atomic search query. Search capabilities are generated for a secondary atomic search query using the primary atomic search query and the secondary atomic search query. Such methods mask query data and the actual composition of the database to reduce computation complexity and privacy leakage.

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Riverdale, NY, United States of America

Hugo M Krawczyk