Bilinear Entropy Expansion from the Decisional Linear Assumption.
Lucas Kowalczyk, Allison Bishop Lewko · 2014
We develop a technique inspired by pseudorandom functions that allows us to increase the entropy available for proving the security of dual system encryption schemes under the Decisional Linear Assumption. We show an application of the tool to Attribute-Based Encryption by presenting a Key-Policy ABE scheme that exhibits a significant improve-ment over the state of the art schemes in public parameter size in terms of the number of attribute-uses allowed in the policy while remaining fully secure under the Decisional Linear Assumption. 1