Spatial encryption is an encryption system within the GIBE model. It is designed as a toolbox from which other encryption systems can be built, using linear algebra as an encoding method. It is based on the work of Boneh, Boyen and Goh, and generalizes hierarchical IBE as well as the hierarchical inner-product encryption of Okamoto and Takashima.
Here we show several new results related to spatial encryption. We show how to build adaptively secure spatial systems (under a compact but nonstandard assumption) using Lewko and Waters' dual-system encryption. In doing this, we also show how to adapt Lewko and Waters' result to a prime-order setting without sacrificing constant-size ciphertexts. We also show new embeddings of other cryptosystems into spatial encryption.
Beyond spatial encryption, we propose a variant called "doubly-spatial encryption", which generalizes both spatial encryption and Attrapadung and Libert's "negated spatial encryption". This generalization adds more flexibility, including more flexible revocation systems and potential improvements in policy language. Unfortunately, we were only able to prove selective security for doubly-spatial encryption, and its ciphertext is no longer constant-size.Category / Keywords: public-key cryptography / identity-based encryption, spatial encryption Publication Info: Stanford University thesis, 2011 Date: received 17 Jul 2011 Contact author: mike at shiftleft org Available format(s): PDF | BibTeX Citation Version: 20110718:193802 (All versions of this report) Discussion forum: Show discussion | Start new discussion