[GPSW06] Attribute-Based Encryption for Fine-Grained Access Control of Encrypted Data

Authors: Vipul Goyal, Omkant Pandey, Amit Sahai, Brent Waters | Venue: CCS 2006 | Source

Abstract

As more sensitive data is shared and stored by third-party sites on the Internet, there will be a need to encrypt data stored at these sites. One drawback of encrypting data, is that it can be selectively shared only at a coarse-grained level (i.e., giving another party your private key). We develop a new cryptographic primitive called Key-Policy Attribute-Based Encryption (KP-ABE), in which ciphertexts are associated with sets of attributes and private keys are associated with access structures that control which ciphertexts a user is able to decrypt. We demonstrate the applicability of our construction to sharing of audit-log information and broadcast encryption. Our construction supports monotone access structures, which can be expressed as monotone Boolean formulas or as Linear Secret-Sharing Schemes (LSSS), and is proved selectively secure under the Decisional Bilinear Diffie-Hellman assumption.