Patent ID: 11347882

Abstract:
Methods and devices for secure data sharing with granular access control are described. A modified attribute-based encryption (ABE) scheme is used to perform cryptographically-enforced ABE using attributes of a file access policy. A sender sends to a receiver a file encrypted using a file encryption key, the file encryption key encrypted using ABE based on a file access policy set by the sender, and a set of private ABE keys decryptable using a key stored in a trusted execution environment (TEE) of the receiver. The private ABE keys are decrypted by the receiver TEE when the file is accessed, decrypting a file encryption key only when the attributes of the receiver access action satisfy the file access policy. The decrypted file encryption key grants access to the file contents via a trusted viewer application. A user password may also be required and cryptographically enforced as part of the ABE decryption.