Sap Se

Kilian Becher

Axel Schroepfer

Mirko Schaefer

Christian Hellwig

Julius Albert Gregor Lagodzinski

Daniel Bernau

Arne Schramm

Johannes Haasen

Lars Baumann

Marcel Muth

A benchmarking service is engineered to provide computing performance metric benchmarks based on computing performance metrics provided from a variety of providers without being exposed to the underlying computing performance metrics. A homomorphic encryption scheme is used in a threshold cryptography scenario that allows aggregation of the computing performance metrics without decrypting the metrics. An independent decryption service can partially decrypt the benchmark, which can ultimately be decrypted to plaintext for use by the provider. Bitwise operations can be defined to address error problems, and the bitwise operations can be constrained to a smaller bit size to avoid proliferation of gates.

Performance benchmarking with cascaded decryption

Methods, systems, and computer-readable storage media for receiving an index and a random number from a verifier, receiving, from a shared data storage, encrypted supply chain data (SCD) of a supply chain actor (SCA), re-encrypting the encrypted SCD to provide re-encrypted SCD using a public encryption key of a decryption party, executing homomorphic operations on the re-encrypted SCD to provide an encrypted blinded result using second random numbers, receiving an encrypted modified blinded result, generating an encrypted blinded verification result using a verification function, the encrypted blinded result, the encrypted modified blinded result, and the random number, and sending the encrypted blinded verification result for decryption to provide a blinded verification result to the verifier, the verifier determining a verification result based on the blinded verification result and the random number, and comparing the verification result to a product claim.

Privacy-preserving supply chain verification for multiple asset types in shared data storage scenarios

Disclosed herein are system, method, and computer program product embodiments for pooling requirements, such as placing of multiple purchase orders, while preserving the privacy of the requirements provided by requesters placing the orders. The approach involves receiving first encrypted information comprising a first request from a first client and second encrypted information comprising a second request from a second client. An encrypted intersection result of the first request and the second request can then be calculated using the first encrypted information and the second encrypted information, in their encrypted form without the need to decrypt either.

Method, system, and non-transitory computer readable storage device for a pooling requirement while preserving privacy

Systems and methods include determination of a first value to be blinded, determination of a first key value, generation of a first composite value based on the first value and the first key value, performance of a hash operation on the first composite value to generate a first hash value, seeding of a pseudorandom generator with the first hash value to generate a first pseudorandom value, truncation of the first hash value based on the first pseudorandom value to generate a first truncated value, and generation of a blinded value associated with the first value based on a blinding function comprising the first value and the first truncated value.

Deterministic random blinding

The present disclosure involves systems, software, and computer implemented methods for a efficient distributed secret shuffle protocol for encrypted database entries using independent shufflers. Each of multiple data providers provides an encrypted secret input value. A set of shuffling clients, independent of the data providers, participate with a service provider in a secret shuffling of the encrypted secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a rerandomized encrypted secret input value. As a result, the rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.

Efficient distributed secret shuffle protocol for encrypted database entries using independent shufflers

The present disclosure involves systems, software, and computer implemented methods for a communication-efficient secret shuffle protocol for encrypted data based on homomorphic encryption and oblivious transfer. A service provider and multiple clients participate in a secret shuffle protocol of randomly shuffling encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values, including use of an oblivious transfer mechanism. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a client-specific rerandomized encrypted secret input value. As a result, the client-specific rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.

Communication-efficient secret shuffle protocol for encrypted data based on homomorphic encryption and oblivious transfer

A producer may supply amounts xof a good to a plurality of consumers Cin a series of transactions and be subject to a mass balancing verification protocol after every K transactions. A producer platform may compute K random shares (rthrough r) of a random value r, publish blinded amounts trepresenting x+rto a secure, distributed transaction ledger, and transmit an encrypted rto consumer Cusing an asymmetric cryptosystem. A consumer platform may receive and decrypt r(while the consumer Ci actually receives an amount {circumflex over (x)}of the good from the producer), compute {circumflex over (x)}+rand generate a fraud alert signal if it differs from the published t. The consumer platform may also transmit an encrypted rolling sum value to a next consumer C. A verifier platform may, after K transactions, execute the mass balance verification protocol to determine a total amount of the good that the producer had collectively supplied to the consumers C. The verifier platform may also generate a fraud alert signal when appropriate based on the total amount and a maximum allowed amount.

Distributed ledger based mass balancing via secret sharing

The present disclosure involves systems, software, and computer implemented methods for a efficient distributed secret shuffle protocol for encrypted database entries using dependent shufflers. Each of multiple clients provides an encrypted client-specific secret input value. A subset of clients are shuffling clients who participate with a service provider in a secret shuffling of the encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a client-specific rerandomized encrypted secret input value. As a result, the client-specific rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.

Efficient distributed secret shuffle protocol for encrypted database entries using dependent shufflers

The present disclosure involves systems, software, and computer implemented methods for a verifiable communication-efficient secret shuffle protocol for encrypted data based on homomorphic encryption. A service provider and multiple clients participate in a secret shuffle protocol of randomly shuffling encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations, different blinding values, and use of random secret-shares. A protocol step includes homomorphic operations to shuffle encrypted secret input values so that resulting encrypted secret input values are rerandomized and in a shuffled sequence that is unmapped to an order of receipt by the service provider of the encrypted secret input values.

Verifiable secret shuffle protocol for encrypted data based on homomorphic encryption and secret sharing

The present disclosure involves systems, software, and computer implemented methods for verifying encrypted data provider data on a public storage medium. One example method includes receiving a verification request to verify encrypted data provider data stored on a public storage medium. Public storage medium entries relevant to the verification request are identified and retrieved. A homomorphic cryptosystem is used to homomorphically calculate a first encrypted target function result based on encrypted data provider data. The homomorphic cryptosystem and a verifying entity cryptosystem are used to re-encrypt the first encrypted target function result to generate a second encrypted target function result that is encrypted under the verifying entity cryptosystem and not encrypted under the homomorphic cryptosystem. The second encrypted target function result is provided to the verifying entity, to enable the verifying entity to decrypt the second encrypted target function result and verify a target function result.

Verifying a result using encrypted data provider data on a public storage medium

Disclosed herein are computer-implemented method, system, and computer-program product (computer-readable storage medium) embodiments for benchmarking with statistics in a way that reduces leakage, preserving privacy of participants and secrecy of participant data. An embodiment includes receiving a plurality of encrypted values and computing a composite statistic corresponding to at least a subset of the plurality of encrypted values. An embodiment may further include outputting the at least one composite statistic. The composite statistic may be calculated to be distinct from any encrypted value of the plurality of encrypted values, thereby preserving privacy. Further embodiments may also include generating a comparison between the composite statistic and a given encrypted value of the plurality of encrypted values, as well as outputting a result of the comparison. In some embodiments, encrypted values may be encrypted using at least one encryption key, for example, according to a homomorphic or semi-homomorphic encryption scheme.

Privacy-preserving benchmarking with interval statistics reducing leakage

The present disclosure involves systems, software, and computer implemented methods for a communication-efficient secret shuffle protocol for encrypted data based on homomorphic encryption. A service provider and multiple clients participate in a secret shuffle protocol of randomly shuffling encrypted client-specific secret input values. The protocol includes generation and exchange of random numbers, random permutations and different blinding values. A last protocol step includes using homomorphism, for each client, to perform computations on intermediate encrypted data to homomorphically remove a first blinding value and a second blinding value, to generate a client-specific rerandomized encrypted secret input value. As a result, the client-specific rerandomized encrypted secret input values are generated in an order that is unmapped to an order of receipt, at the service provider, of the encrypted secret input values.

Computation-efficient secret shuffle protocol for encrypted data based on homomorphic encryption

Embodiments allow comparison of key figures (e.g., costs, lead times) between different entities in a privacy-preserving manner, utilizing secure multi-party computation (MPC) approaches implemented by a central service provider. The central service provider receives encrypted key figure data from each of multiple players in a peer group. In one embodiment the central service provider executes a secure computation protocol comprising a semi-homomorphic encryption scheme exhibiting an additive homomorphic property. The central service provider returns to each player, a statistical measure (e.g., top quartile, bottom quartile) allowing comparison with the other players' key figures while preserving privacy. Alternative embodiments may return to the players, a statistical measure calculated from a Boolean or arithmetic circuit implemented at the central server using other secure computation approaches (e.g., garbled circuits, secret sharing, or (semi or fully) homomorphic encryption. Embodiments may find value in maintaining privacy of key figure data shared between competitors for benchmarking.

Private benchmarking cloud service with enhanced statistics

A blockchain service receives a first request to insert a first value associated with a transaction into a blockchain. In response, the blockchain service calls a commitment service to obtain a commitment based on the first value. The blockchain service then inserts the commitment into the blockchain at a block associated with the transaction. When the blockchain service subsequently receives a second request to confirm whether a second value matches the first value, it can obtain the commitment from the blockchain. This obtained commitment is then passed to the commitment service along with the second value. The blockchain service then receives a confirmation from the commitment service whether the first value matches the second value. The blockchain service can provide a reply to the second request encapsulating the confirmation. Other variations are provided in which residual amount values can be confirmed. Related apparatus, systems, techniques and articles are also described.

Growing community of inventors

Dresden, Germany

Kilian Becher