8,829 research outputs found
An Elliptic Curve-based Signcryption Scheme with Forward Secrecy
An elliptic curve-based signcryption scheme is introduced in this paper that
effectively combines the functionalities of digital signature and encryption,
and decreases the computational costs and communication overheads in comparison
with the traditional signature-then-encryption schemes. It simultaneously
provides the attributes of message confidentiality, authentication, integrity,
unforgeability, non-repudiation, public verifiability, and forward secrecy of
message confidentiality. Since it is based on elliptic curves and can use any
fast and secure symmetric algorithm for encrypting messages, it has great
advantages to be used for security establishments in store-and-forward
applications and when dealing with resource-constrained devices.Comment: 13 Pages, 5 Figures, 2 Table
Lattice-Based Group Signatures: Achieving Full Dynamicity (and Deniability) with Ease
In this work, we provide the first lattice-based group signature that offers
full dynamicity (i.e., users have the flexibility in joining and leaving the
group), and thus, resolve a prominent open problem posed by previous works.
Moreover, we achieve this non-trivial feat in a relatively simple manner.
Starting with Libert et al.'s fully static construction (Eurocrypt 2016) -
which is arguably the most efficient lattice-based group signature to date, we
introduce simple-but-insightful tweaks that allow to upgrade it directly into
the fully dynamic setting. More startlingly, our scheme even produces slightly
shorter signatures than the former, thanks to an adaptation of a technique
proposed by Ling et al. (PKC 2013), allowing to prove inequalities in
zero-knowledge. Our design approach consists of upgrading Libert et al.'s
static construction (EUROCRYPT 2016) - which is arguably the most efficient
lattice-based group signature to date - into the fully dynamic setting.
Somewhat surprisingly, our scheme produces slightly shorter signatures than the
former, thanks to a new technique for proving inequality in zero-knowledge
without relying on any inequality check. The scheme satisfies the strong
security requirements of Bootle et al.'s model (ACNS 2016), under the Short
Integer Solution (SIS) and the Learning With Errors (LWE) assumptions.
Furthermore, we demonstrate how to equip the obtained group signature scheme
with the deniability functionality in a simple way. This attractive
functionality, put forward by Ishida et al. (CANS 2016), enables the tracing
authority to provide an evidence that a given user is not the owner of a
signature in question. In the process, we design a zero-knowledge protocol for
proving that a given LWE ciphertext does not decrypt to a particular message
Interest-Based Access Control for Content Centric Networks (extended version)
Content-Centric Networking (CCN) is an emerging network architecture designed
to overcome limitations of the current IP-based Internet. One of the
fundamental tenets of CCN is that data, or content, is a named and addressable
entity in the network. Consumers request content by issuing interest messages
with the desired content name. These interests are forwarded by routers to
producers, and the resulting content object is returned and optionally cached
at each router along the path. In-network caching makes it difficult to enforce
access control policies on sensitive content outside of the producer since
routers only use interest information for forwarding decisions. To that end, we
propose an Interest-Based Access Control (IBAC) scheme that enables access
control enforcement using only information contained in interest messages,
i.e., by making sensitive content names unpredictable to unauthorized parties.
Our IBAC scheme supports both hash- and encryption-based name obfuscation. We
address the problem of interest replay attacks by formulating a mutual trust
framework between producers and consumers that enables routers to perform
authorization checks when satisfying interests from their cache. We assess the
computational, storage, and bandwidth overhead of each IBAC variant. Our design
is flexible and allows producers to arbitrarily specify and enforce any type of
access control on content, without having to deal with the problems of content
encryption and key distribution. This is the first comprehensive design for CCN
access control using only information contained in interest messages.Comment: 11 pages, 2 figure
Security and Privacy Issues in Wireless Mesh Networks: A Survey
This book chapter identifies various security threats in wireless mesh
network (WMN). Keeping in mind the critical requirement of security and user
privacy in WMNs, this chapter provides a comprehensive overview of various
possible attacks on different layers of the communication protocol stack for
WMNs and their corresponding defense mechanisms. First, it identifies the
security vulnerabilities in the physical, link, network, transport, application
layers. Furthermore, various possible attacks on the key management protocols,
user authentication and access control protocols, and user privacy preservation
protocols are presented. After enumerating various possible attacks, the
chapter provides a detailed discussion on various existing security mechanisms
and protocols to defend against and wherever possible prevent the possible
attacks. Comparative analyses are also presented on the security schemes with
regards to the cryptographic schemes used, key management strategies deployed,
use of any trusted third party, computation and communication overhead involved
etc. The chapter then presents a brief discussion on various trust management
approaches for WMNs since trust and reputation-based schemes are increasingly
becoming popular for enforcing security in wireless networks. A number of open
problems in security and privacy issues for WMNs are subsequently discussed
before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the
author's previous submission in arXiv submission: arXiv:1102.1226. There are
some text overlaps with the previous submissio
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