Visa International Service Association

Rohit Sinha

Sivanarayana Gaddam

Ranjit Kumar Kumaresan

Mihai Christodorescu

Atul Luykx

Gaven James Watson

Hao Yang

Srinivasan Raghuraman

Pratyay Mukherjee

Abhinav Aggarwal

Yogesh Lokhande

Described herein are a system and techniques for enabling user control over usage of their information by data consumers, even when untrusted parties are involved, while also preventing collusion between the untrusted party and a data consumer. A user's information may be collected by a client device and provided to a host server. An encrypted version of the user's information may be stored at the host server so that it is processed on a private enclave of the host server. When the data is to be provided to multiple data consumers, the data may be encrypted for each of the data consumers and may be released to each of those data consumers simultaneously once confirmation has been received that the data has been made available to each of the data consumers.

Techniques for preventing collusion using simultaneous key release

Verification system and methods are provided for allowing database server responses to be verified. A proxy device may maintain a data structure (e.g., a Merkle B+-tree) within a secure memory space (e.g., an Intel SGX enclave) associated with a protected application. In some embodiments, the data structure may comprise hashed values representing hashed versions of the data managed by the database server. The proxy may intercept client requests submitted from a client device and forward such requests to the database server. Responses from the database server may be verified using the data structure (e.g., the hashes contained in the Merkle B+-tree). If the data is verified by the proxy device, the response may be transmitted to the client device.

High-throughput data integrity via trusted computing

Described are a system and method for secure n-party computation. The method includes communicating a first input of an n-party computation to a trusted execution environment (TEE). The method also includes receiving, from the TEE, at least one encrypted output of the n-party computation using the first input and at least one second input of at least one other computing device, and using at least one public key of the at least one other computing device. The method further includes posting the at least one encrypted output on at least one blockchain accessible by the at least one other computing device. The method further includes, in response to posting the at least one encrypted output, receiving at least one proof of publication. The method further includes communicating the at least one proof of publication to the TEE and receiving the function output of the n-party computation.

System and method for fair, secure n-party computation using at least one blockchain

Described are a system, method, and computer program product for secure real-time n-party computation. The method includes communicating, to a trusted execution environment (TEE), a first computation input and a first portion of a one-time key. The method also includes receiving, from the TEE, an encrypted output of a computation based on the first computation input and a second computation input communicated to the TEE by a second computing device. The method further includes communicating the encrypted output to the second computing device and receiving a digital signature indicating that the second computing device received the encrypted output. The method further includes communicating the first portion of the one-time key to the second computing device and, in response to not receiving the second portion of the one-time key from the second computing device, executing a fallback computation process using the TEE and a shared ledger to determine the computation.

System, method, and computer program product for secure real-time n-party computation

A method, system, and computer program product generate, with a payment network, a first value (a) and a second value (g), the second value (g) generated based on the first value (a) and a generator value (g); generate, with the payment network, a plurality of random merchant numbers (m) for a respective plurality of merchant banks; determine, with the payment network, a merchant product (M) based on a product of the plurality of random merchant numbers (m); generate, with the payment network, a public key (pk) based on the second value (g), the merchant product (M), and the random merchant number (m) and a random key (rk) based on the merchant product (M) and the random merchant number (m) for each respective merchant bank; and communicate, with the payment network, the public key (pk) and the random key (rk) to at least one respective merchant bank.

Method, system, and computer program product for network bound proxy re-encryption and PIN translation

A method, system, and computer program product generate, with a payment network, a first value (a) and a second value (ga), the second value (ga) based on the first value (a) and a generator value (g); generate, with the payment network, a plurality of random merchant numbers (mi) for a respective plurality of merchant banks; determine, with the payment network, a merchant product (M) based on a product of the plurality of random merchant numbers (mi); generate, with the payment network, a public key (pki) based on the second value (ga), the merchant product (M), and the random merchant number (mi) and a random key (rki) based on the merchant product (M) and the random merchant number (mi) for each respective merchant bank; and communicate, with the payment network, the public key (pki) and the random key (rki) to at least one respective merchant bank.

Methods and systems for secure multi-party generation of random bits are disclosed. These random bits can be generated securely, even if some parties (i.e., less than a corruption threshold) are dishonest or malicious. Methods and systems can use secure environments in order to securely generate and store cryptographic keys. Using broadcast protocols such as Dolev-Strong, a generator computer can distribute a public protocol instance key to other participant computers. Each participant computer can generate a random bit and encrypted the random bit with the public protocol instance key, and broadcast its encrypted random bit to the other participant computers. Once each participant computer has received the encrypted random bits from all other participant computers, the private protocol instance key can be released to the participant computers, enabling the participant computers to decrypt the encrypted random bits, and calculate an output random bit based on the encrypted random bits.

Secure multi-party random bit generation

The system and methods described herein may be utilized to perform operations in a faster and less complex manner than provided by conventional systems. An encrypted record may be stored at a user device. The encrypted record may include entries related to operations that were previously requested by the user device. The encrypted record may have been encrypted using a dynamic value and a key that is associated with an entity associated with the user. A recipient computer of a request by the user device may be configured to utilize the dynamic value provided in the request and the key associated with the entity to derive the encryption key(s) last used to encrypt the record. The recipient computer may decrypt and modify the decrypted record to perform the requested operation while the user device is precluded from doing so.

Techniques for performing secure operations

The system and methods described herein may be utilized to perform operations in a faster and less complex manner than provided by conventional systems. An encrypted record may be stored at a user device. The encrypted record may include entries related to operations that were previously requested by the user device. The encrypted record may have been encrypted using a dynamic value and a key that is associated with an entity associated with the user. A recipient computer of a request by the user device may be configured to utilize the dynamic value provided in the request and the key associated with the entity to derive the encryption key(s) last used to encrypt the record. The recipient computer may decrypt and modify the encrypted record to perform the requested operation while the user device is precluded from doing so.

A method, system, and computer program product generate, with a payment network, a first value (a) and a second value (ga), the second value (ga) generated based on the first value (a) and a generator value (g); generate, with the payment network, a plurality of random merchant numbers (mi) for a respective plurality of merchant banks; determine, with the payment network, a merchant product (M) based on a product of the plurality of random merchant numbers (mi); generate, with the payment network, a public key (pki) based on the second value (ga), the merchant product (M), and the random merchant number (mi) and a random key (rki) based on the merchant product (M) and the random merchant number (mi) for each respective merchant bank; and communicate, with the payment network, the public key (pki) and the random key (rki) to at least one respective merchant bank.

Method, system, and computer program product for network bound proxy re-encryption and pin translation

A technique for oblivious filtering may include receiving an input data stream having a plurality of input elements. For each of the input elements received, a determination is made as to whether the input element satisfies a filtering condition. For each of the input elements received that satisfies the filtering condition, a write operation is performed to store the input element in a memory subsystem. For those of the input elements received that do not satisfy the filtering condition, at least a dummy write operation is performed on the memory subsystem. The contents of the memory subsystem can be evicted to an output data stream when the memory subsystem is full. The memory subsystem may include a trusted memory and an unprotected memory.

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San Jose, CA, United States of America

Rohit Sinha