2 research outputs found
Lattice-based Unidirectional IBPRE Secure in Standard Model
Proxy re-encryption (PRE) securely enables the re-encryption of ciphertexts
from one key to another, without relying on trusted parties, i.e., it offers
delegation of decryption rights. PRE allows a semi-trusted third party termed
as a "proxy" to securely divert encrypted files of user A (delegator) to user B
(delegatee) without revealing any information about the underlying files to the
proxy. To eliminate the necessity of having a costly certificate verification
process, Green and Ateniese introduced an identity-based PRE (IB-PRE). The
potential applicability of IB-PRE leads to intensive research from its first
instantiation. Unfortunately, till today, there is no unidirectional IB-PRE
secure in the standard model, which can withstand quantum attack. In this
paper, we provide, for the first time, a concrete construction of
unidirectional IB-PRE which is secure in standard model based on the hardness
of learning with error problem. Our technique is to use the novel trapdoor
delegation technique of Micciancio and Peikert. The way we use trapdoor
delegation technique may prove useful for functionalities other than proxy
re-encryption as well
Collusion-Resistant Identity-based Proxy Re-Encryption: Lattice-based Constructions in Standard Model
The concept of proxy re-encryption (PRE) dates back to the work of Blaze,
Bleumer, and Strauss in 1998. PRE offers delegation of decryption rights, i.e.,
it securely enables the re-encryption of ciphertexts from one key to another,
without relying on trusted parties. PRE allows a semi-trusted third party
termed as a ``proxy" to securely divert encrypted files of user A (delegator)
to user B (delegatee) without revealing any information about the underlying
files to the proxy. To eliminate the necessity of having a costly certificate
verification process, Green and Ateniese introduced an identity-based PRE
(IB-PRE). The potential applicability of IB-PRE sprung up a long line of
intensive research from its first instantiation. Unfortunately, till today,
there is no collusion-Resistant unidirectional IB-PRE secure in the standard
model, which can withstand quantum attack. In this paper, we present the first
concrete constructions of collusion-Resistant unidirectional IB-PRE, for both
selective and adaptive identity, which are secure in standard model based on
the hardness of learning with error problem.Comment: arXiv admin note: substantial text overlap with arXiv:2005.0674