57,787 research outputs found
New Digital Signature Algorithm EHTv2
Every public-key encryption/decryption algorithm where the
set of possible plain-texts is identical to the set of possible cipher-texts
may be converted into a digital signature algorithm. That is quite different
in the lattice (code)-based public-key cryptography. The decryption algorithm on a random input produces a valid plain-text, that is a signature, with a negligible probability. That explains why it is so difficult to construct a new secure and efficient lattice-based digital signature system. Though several solutions are known and taking part in the NIST Post Quantum Standardisation Process there is still a need to construct digital signature algorithms based on new principles. In this work, a new and efficient digital signature algorithm is suggested. Its design is simple and transparent. Its security is based on the hardness of an approximate closest vector problem in the maximum norm for some q-ary lattices. The signature is several times shorter than that provided by the NIST Selected Digital Signature Algorithms with comparable security level, while the public key size is larger
A Novel Digital Signature based on Error Correcting Codes
A digital signature is a cryptographic primitive for ensuring the authenticity of digital documents. A valid digital signature allows checking that a message was created by a known sender (authentication), that the sender cannot deny having sent the message (nonrepudiation), and that the message was not altered in transit (integrity).The idea of constructing practical signatures based on error correcting codes was introduced by Courtois et al in [1]. The main goal is to make digital signature for which the security is based on decoding syndrome problem. In this paper, a new construction of digital signature is considered which is an extension of the error correcting code construction. The proposed method consists of reordering the message bits to get a decodable word. Then apply an efficient decoding algorithm to get signature
Cloud Data Auditing Using Proofs of Retrievability
Cloud servers offer data outsourcing facility to their clients. A client
outsources her data without having any copy at her end. Therefore, she needs a
guarantee that her data are not modified by the server which may be malicious.
Data auditing is performed on the outsourced data to resolve this issue.
Moreover, the client may want all her data to be stored untampered. In this
chapter, we describe proofs of retrievability (POR) that convince the client
about the integrity of all her data.Comment: A version has been published as a book chapter in Guide to Security
Assurance for Cloud Computing (Springer International Publishing Switzerland
2015
Cryptanalysis of a One-Time Code-Based Digital Signature Scheme
We consider a one-time digital signature scheme recently proposed by
Persichetti and show that a successful key recovery attack can be mounted with
limited complexity. The attack we propose exploits a single signature
intercepted by the attacker, and relies on a statistical analysis performed
over such a signature, followed by information set decoding. We assess the
attack complexity and show that a full recovery of the secret key can be
performed with a work factor that is far below the claimed security level. The
efficiency of the attack is motivated by the sparsity of the signature, which
leads to a significant information leakage about the secret key.Comment: 5 pages, 1 figur
Using LDGM Codes and Sparse Syndromes to Achieve Digital Signatures
In this paper, we address the problem of achieving efficient code-based
digital signatures with small public keys. The solution we propose exploits
sparse syndromes and randomly designed low-density generator matrix codes.
Based on our evaluations, the proposed scheme is able to outperform existing
solutions, permitting to achieve considerable security levels with very small
public keys.Comment: 16 pages. The final publication is available at springerlink.co
A tight security reduction in the quantum random oracle model for code-based signature schemes
Quantum secure signature schemes have a lot of attention recently, in
particular because of the NIST call to standardize quantum safe cryptography.
However, only few signature schemes can have concrete quantum security because
of technical difficulties associated with the Quantum Random Oracle Model
(QROM). In this paper, we show that code-based signature schemes based on the
full domain hash paradigm can behave very well in the QROM i.e. that we can
have tight security reductions. We also study quantum algorithms related to the
underlying code-based assumption. Finally, we apply our reduction to a concrete
example: the SURF signature scheme. We provide parameters for 128 bits of
quantum security in the QROM and show that the obtained parameters are
competitive compared to other similar quantum secure signature schemes
Computational and Energy Costs of Cryptographic Algorithms on Handheld Devices
Networks are evolving toward a ubiquitous model in which heterogeneous
devices are interconnected. Cryptographic algorithms are required for developing security
solutions that protect network activity. However, the computational and energy limitations
of network devices jeopardize the actual implementation of such mechanisms. In this
paper, we perform a wide analysis on the expenses of launching symmetric and asymmetric
cryptographic algorithms, hash chain functions, elliptic curves cryptography and pairing
based cryptography on personal agendas, and compare them with the costs of basic operating
system functions. Results show that although cryptographic power costs are high and such
operations shall be restricted in time, they are not the main limiting factor of the autonomy
of a device
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