510 research outputs found
Short Group Signatures via Structure-Preserving Signatures: Standard Model Security from Simple Assumptions
International audienceGroup signatures are a central cryptographic primitive which allows users to sign messages while hiding their identity within a crowd of group members. In the standard model (without the random oracle idealization), the most efficient constructions rely on the Groth-Sahai proof systems (Euro-crypt'08). The structure-preserving signatures of Abe et al. (Asiacrypt'12) make it possible to design group signatures based on well-established, constant-size number theoretic assumptions (a.k.a. " simple assumptions ") like the Symmetric eXternal Diffie-Hellman or Decision Linear assumptions. While much more efficient than group signatures built on general assumptions, these constructions incur a significant overhead w.r.t. constructions secure in the idealized random oracle model. Indeed, the best known solution based on simple assumptions requires 2.8 kB per signature for currently recommended parameters. Reducing this size and presenting techniques for shorter signatures are thus natural questions. In this paper, our first contribution is to significantly reduce this overhead. Namely, we obtain the first fully anonymous group signatures based on simple assumptions with signatures shorter than 2 kB at the 128-bit security level. In dynamic (resp. static) groups, our signature length drops to 1.8 kB (resp. 1 kB). This improvement is enabled by two technical tools. As a result of independent interest, we first construct a new structure-preserving signature based on simple assumptions which shortens the best previous scheme by 25%. Our second tool is a new method for attaining anonymity in the strongest sense using a new CCA2-secure encryption scheme which is simultaneously a Groth-Sahai commitment
Reconfigurable Security: Edge Computing-based Framework for IoT
In various scenarios, achieving security between IoT devices is challenging
since the devices may have different dedicated communication standards,
resource constraints as well as various applications. In this article, we first
provide requirements and existing solutions for IoT security. We then introduce
a new reconfigurable security framework based on edge computing, which utilizes
a near-user edge device, i.e., security agent, to simplify key management and
offload the computational costs of security algorithms at IoT devices. This
framework is designed to overcome the challenges including high computation
costs, low flexibility in key management, and low compatibility in deploying
new security algorithms in IoT, especially when adopting advanced cryptographic
primitives. We also provide the design principles of the reconfigurable
security framework, the exemplary security protocols for anonymous
authentication and secure data access control, and the performance analysis in
terms of feasibility and usability. The reconfigurable security framework paves
a new way to strength IoT security by edge computing.Comment: under submission to possible journal publication
An Effective Private Data storage and Retrieval System using Secret sharing scheme based on Secure Multi-party Computation
Privacy of the outsourced data is one of the major challenge.Insecurity of
the network environment and untrustworthiness of the service providers are
obstacles of making the database as a service.Collection and storage of
personally identifiable information is a major privacy concern.On-line public
databases and resources pose a significant risk to user privacy, since a
malicious database owner may monitor user queries and infer useful information
about the customer.The challenge in data privacy is to share data with
third-party and at the same time securing the valuable information from
unauthorized access and use by third party.A Private Information Retrieval(PIR)
scheme allows a user to query database while hiding the identity of the data
retrieved.The naive solution for confidentiality is to encrypt data before
outsourcing.Query execution,key management and statistical inference are major
challenges in this case.The proposed system suggests a mechanism for secure
storage and retrieval of private data using the secret sharing technique.The
idea is to develop a mechanism to store private information with a highly
available storage provider which could be accessed from anywhere using queries
while hiding the actual data values from the storage provider.The private
information retrieval system is implemented using Secure Multi-party
Computation(SMC) technique which is based on secret sharing. Multi-party
Computation enable parties to compute some joint function over their private
inputs.The query results are obtained by performing a secure computation on the
shares owned by the different servers.Comment: Data Science & Engineering (ICDSE), 2014 International Conference,
CUSA
RHyTHM: A Randomized Hybrid Scheme To Hide in the Mobile Crowd
Any on-demand pseudonym acquisition strategy is problematic should the
connectivity to the credential management infrastructure be intermittent. If a
vehicle runs out of pseudonyms with no connectivity to refill its pseudonym
pool, one solution is the on-the-fly generation of pseudonyms, e.g., leveraging
anonymous authentication. However, such a vehicle would stand out in the crowd:
one can simply distinguish pseudonyms, thus signed messages, based on the
pseudonym issuer signature, link them and track the vehicle. To address this
challenge, we propose a randomized hybrid scheme, RHyTHM, to enable vehicles to
remain operational when disconnected without compromising privacy: vehicles
with valid pseudonyms help others to enhance their privacy by randomly joining
them in using on-the-fly self-certified pseudonyms along with aligned
lifetimes. This way, the privacy of disconnected users is enhanced with a
reasonable computational overhead.Comment: 4 pages, 4 figures, IEEE Vehicular Networking Conference (VNC),
November 27-29, 2017, Torino, Ital
A Light-Weight Group Signature Scheme for Wireless Networks Based-on BBS Short Group Signature
In the natural context of wireless network environment,
the communications between wireless nodes are more easily observed for the goal of the network traffic analysis. Thus, to enable a secure and anonymous communication system from thwarting of such analysis attacks would be strongly desirable. In this paper, we propose a secure and anonymous communication system using pairing-based group signatures. The achievement of secure and anonymous communication is performed by allowing all valid member wireless nodes of a
particular privilege group to authenticate each other without revealing their own identitie
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