Abstract: An access control system is disclosed for controlling access to a resource. A request is received by a location attribute policy (LAP) server to access an encrypted resource. The LAP server accesses a resource policy that identifies requirements for granting access to the encrypted resource, such as a list of attributes of the requestor that are required and a dynamic attribute requirement of the requestor. The LAP server receives a cryptographic proof from the computing device that the requestor possesses the attributes and validates the proof based at least on information obtained from a trusted ledger. Once the proof is validated, the LAP server provides a shared secret associated with the dynamic attribute requirement to a decryption algorithm. The decryption algorithm uses the dynamic attribute shared secret in combination with one or more attribute shared secrets from the requestor to generate a decryption key for the encrypted resource.

Abstract: Embodiments described herein enable at least one of a plurality of entities to access data protected by a security policy in response to validating respective digital access requests from the entities. The respective digital access requests are received, each comprising a proof. For each request, an encrypted secret share is obtained from a respective ledger database. Each request is validated based at least on the respective encrypted secret share and the proof, without decrypting the respective encrypted secret share. In response to validating all of the requests, a verification that an access criteria of a security policy is met is made. If so, at least one of the entities is provided with access to data protected by the security policy. In an aspect, embodiments enable a blind subpoena to be performed. In another aspect, embodiments enable the at least one entity to access the data for an isolated purpose.

Abstract: In one embodiment, a service receives a one or more digests to verify a plurality of requests that were performed by a request handler for one or more clients. The digests summarize processing of the plurality of requests using a first contract. The information for the one or more digests is stored in a plurality of blocks in a distributed ledger. A second contract is executed to verify the processing of the plurality of requests. The second contract generates a first set that stores states for reads of values from the data store; generates a second set that stores states for values written to the data store, and verifies the processing by checking states in the first set are a subset of states in the second set.

Abstract: This document relates to hardware protection of differential privacy techniques. One example obtains multiple instances of encrypted telemetry data within a secure enclave and processes the encrypted telemetry data to obtain multiple instances of unencrypted telemetry data. The example also processes, within the secure enclave, the multiple instances of unencrypted telemetry data to obtain a perturbed aggregate. The example also releases the perturbed aggregate from the secure enclave.