Paper Info
Title
Adaptively Secure Identity-Based Encryption from Lattices with Asymptotically Shorter Public Parameters.
Abstract
In this paper, we present two new adaptively secure identity-based encryption IBE schemes from lattices. The size of the public parameters, ciphertexts, and private keys are $$\\tilde{O}n^2 \\kappa ^{1/d}$$, $$\\tilde{O}n$$, and $$\\tilde{O}n$$ respectively. Here, n is the security parameter, $$\\kappa $$ is the length of the identity, and $$d\\in \\mathbb {N}$$ is a flexible constant that can be set arbitrary but will affect the reduction cost. Ignoring the poly-logarithmic factors hidden in the asymptotic notation, our schemes achieve the best efficiency among existing adaptively secure IBE schemes from lattices. In more detail, our first scheme is anonymous, but proven secure under the LWE assumption with approximation factor $$n^{\\omega 1}$$. Our second scheme is not anonymous, but proven adaptively secure assuming the LWE assumption for all polynomial approximation factors. As a side result, based on a similar idea, we construct an attribute-based encryption scheme for branching programs that simultaneously satisfies the following properties for the first time: Our scheme achieves compact secret keys, the security is proven under the LWE assumption with polynomial approximation factors, and the scheme can deal with unbounded length branching programs.
Year
DOI
Venue
2016
10.1007/978-3-662-49896-5_2
IACR Cryptology ePrint Archive
Field
DocType
Volume
Discrete mathematics,Combinatorics,Big O notation,Lattice (order),Polynomial,Encryption,Theoretical computer science,Tilde,Omega,Security parameter,Mathematics,Branching (version control)
Journal
2016
ISSN
Citations 
PageRank 
0302-9743
7
0.48
References 
Authors
35
1
Name
Order
Citations
PageRank
Shota Yamada19418.10