A Verifiable Multi-Recipient Encryption Scheme
from Multilinear Maps
Zhengjun Jing, Guoping Jiang
College of Computer
Nanjing University of Posts and Telecommunications
Nanjing, China
jzjing@jsut.edu.cn, jianggp@njupt.edu.cn
Chunsheng Gu
Department of Computer Engineering
Jiangsu University of Technology
Changzhou, China
guchunsheng@gmail.com
Abstract—Multi-recipient encryption is an important
public key cryptosystem, which can be applied for a
variety of purposes, such as broadcasting data. In order to
design an secure multi-recipient public key encryption
(MRPKE) in post-quantum era, in this paper, we construct
a novel MRPKE scheme base on Garg-Gentry-Halevi
(GGH) framework which is a graded algebras analogue of
multilinear maps from ideal lattice. Under the grade
decisional Diffie-Hellman (GDDH) assumption of GGH,
the proposed scheme has semantically safety against
chosen plaintext attack (CPA). At the same time, each
recipient, without first decrypting, can verify whether the
message to be received is from a legitimate sender.
Furthermore, the encryption and decryption only involves
the polynomial modular addition and multiplication in
polynomial ring, so the efficiency of the proposed scheme
is higher.
Keywords—
public key encryption; multi-recipient
verifiable; multilinear maps
I.
INTRODUCTION
In 2000, Bellare et al.[1] and Baudron et al.[2]
independently proposed the concept of multi-recipient public
key encryption and its security definitions. A multi-recipient
public key encryption system generally includes a sender and
n receivers, in which both the sender and receivers have their
own private and public key pairs denoted by
(,)
ii
pk sk ,
where
0 in and
00
(,)pk sk is for the sender. The sender can
use his (or her) private key and the
n public keys of recipients
to encrypt the message
M , while any authorized recipient can
use own private key to decrypt the received ciphertext, and
obtain the correct plaintext message. Such properties of multi-
recipient public key encryption can be applied for a variety of
purposes, such as broadcasting encryption and multicast
security protocols in wireless sensor network.
The initial MRPKE schemes were just an extension of the
general public key encryption (such as 2-party) [1-3]. For
n
receivers, they needed to encrypt
n times to generate the
ciphertext
1
(, )
n
CCC " . Obviously, such MRPKE schemes
were less efficient and high bandwidth requirements in
communication. To improve the efficiency, Lu et al. [4]and
Pang et al. [5] respectively proposed new schemes based on the
Shamir’s secrets sharing protocol and bilinear paring on elliptic
curve, in which the message to be sent was encrypted only
once while the corresponding ciphertext could be decrypted by
multiple private keys. After the invention of identity-based
public key encryption system[6], many outstanding identity-
based multi-recipient public key encryption schemes had also
been proposed. Furthermore, the formal definition of security
of MRPKE was described[7]. In order to protect the privacy of
users, several MRPKE schemes with anonymity of receipts (or
the sender) were proposed [8-10]. Recently, Pang et al.
designed a new identity-based multi-recipient public key
encryption scheme[11] , which can not only ensure the
anonymity of the recipients, but also satisfy the fairness and
make the identity of the sender verifiable. However, with the
increase in the number of recipients, the ciphertext length of
schemes described above becomes longer. More importantly,
the security of all these schemes is based on the elliptic curve
bilinear paring, which is threatened by the power of quantum
computers.
In order to design a secure multi-recipient public key
encryption in post-quantum era, in this paper, we construct a
novel MRPKE scheme from GGH multilinear maps. Its
security can be reduced to the assumption that the GDDH
problem is difficult to solve in GGH framework, which is
similar to the NTRU hard assumption[12]. Although GDDH
hard assumption can not be directly reduced to SVP (shortest
vector problem), LWE (Learning with error) and other general
problems about lattice, there is no effective algorithm in
polynomial time to solve this problem, including quantum
algorithms. Under the grade decisional Diffie-Hellman
(GDDH) assumption of GGH, the proposed scheme has
semantically safety against chosen plaintext attack (CPA). At
the same time, each recipient, without first decrypting, can
verify whether the message to be received is from a legitimate
sender. Furthermore, the encryption and decryption only
involves the polynomial modular addition and multiplication in
polynomial ring, so the efficiency of the proposed scheme is
higher.
The rest of this paper is organized as follows. In section 2,
we introduce the background about multilinear map and the
algorithms about GGH framework, while the definition of
MRPKE and its security model is described in section 3. In
2014 Ninth International Conference on P2P, Parallel, Grid, Cloud and Internet Computing
978-1-4799-4171-1/14 $31.00 © 2014 IEEE
DOI 10.1109/3PGCIC.2014.49
151