Authors
Aayush Jain, Huijia Lin, Christian Matt, Amit Sahai
Publication date
2019
Conference
Advances in Cryptology–EUROCRYPT 2019: 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Darmstadt, Germany, May 19–23, 2019, Proceedings, Part I 38
Pages
251-281
Publisher
Springer International Publishing
Description
In this work, we introduce and construct D-restricted Functional Encryption (FE) for any constant , based only on the SXDH assumption over bilinear groups. This generalizes the notion of 3-restricted FE recently introduced and constructed by Ananth et al. (ePrint 2018) in the generic bilinear group model.
A -restricted FE scheme is a secret key FE scheme that allows an encryptor to efficiently encrypt a message of the form $$M=(\varvec{x},\varvec{y},\varvec{z})$$. Here, $$\varvec{x}\in \mathbb {F}_{\mathbf {p}}^{d\times n}$$ and $$\varvec{y},\varvec{z}\in \mathbb {F}_{\mathbf {p}}^n$$. Function keys can be issued for a function $$f=\varSigma _{\varvec{I}= (i_1,..,i_d,j,k)}\ c_{\varvec{I}}\cdot \varvec{x}[1,i_1] \cdots \varvec{x}[d,i_d] \cdot \varvec{y}[j]\cdot \varvec{z}[k]$$ where the coefficients $$c_{\varvec{I}}\in \mathbb {F}_{\mathbf {p}}$$. Knowing the function key and the ciphertext, one can learn $$f …
Scholar articles
A Jain, H Lin, C Matt, A Sahai - Advances in Cryptology–EUROCRYPT 2019: 38th …, 2019