5,974 research outputs found
Security Proofs for Identity-Based Identification and Signature Schemes
This paper provides either security proofs or attacks for a large number of identity-based identification and signature schemes defined either explicitly or implicitly in existing literature. Underlying these is a framework that on the one hand helps explain how these schemes are derived, and on the other hand enables modular security analyses, thereby helping to understand, simplify and unify previous work. We also analyze a generic folklore construction that in particular yields identity-based identification and signature schemes without random oracles
Random Oracles in a Quantum World
The interest in post-quantum cryptography - classical systems that remain
secure in the presence of a quantum adversary - has generated elegant proposals
for new cryptosystems. Some of these systems are set in the random oracle model
and are proven secure relative to adversaries that have classical access to the
random oracle. We argue that to prove post-quantum security one needs to prove
security in the quantum-accessible random oracle model where the adversary can
query the random oracle with quantum states.
We begin by separating the classical and quantum-accessible random oracle
models by presenting a scheme that is secure when the adversary is given
classical access to the random oracle, but is insecure when the adversary can
make quantum oracle queries. We then set out to develop generic conditions
under which a classical random oracle proof implies security in the
quantum-accessible random oracle model. We introduce the concept of a
history-free reduction which is a category of classical random oracle
reductions that basically determine oracle answers independently of the history
of previous queries, and we prove that such reductions imply security in the
quantum model. We then show that certain post-quantum proposals, including ones
based on lattices, can be proven secure using history-free reductions and are
therefore post-quantum secure. We conclude with a rich set of open problems in
this area.Comment: 38 pages, v2: many substantial changes and extensions, merged with a
related paper by Boneh and Zhandr
Efficient and Low-Cost RFID Authentication Schemes
Security in passive resource-constrained Radio Frequency Identification
(RFID) tags is of much interest nowadays. Resistance against illegal tracking,
cloning, timing, and replay attacks are necessary for a secure RFID
authentication scheme. Reader authentication is also necessary to thwart any
illegal attempt to read the tags. With an objective to design a secure and
low-cost RFID authentication protocol, Gene Tsudik proposed a timestamp-based
protocol using symmetric keys, named YA-TRAP*. Although YA-TRAP* achieves its
target security properties, it is susceptible to timing attacks, where the
timestamp to be sent by the reader to the tag can be freely selected by an
adversary. Moreover, in YA-TRAP*, reader authentication is not provided, and a
tag can become inoperative after exceeding its pre-stored threshold timestamp
value. In this paper, we propose two mutual RFID authentication protocols that
aim to improve YA-TRAP* by preventing timing attack, and by providing reader
authentication. Also, a tag is allowed to refresh its pre-stored threshold
value in our protocols, so that it does not become inoperative after exceeding
the threshold. Our protocols also achieve other security properties like
forward security, resistance against cloning, replay, and tracking attacks.
Moreover, the computation and communication costs are kept as low as possible
for the tags. It is important to keep the communication cost as low as possible
when many tags are authenticated in batch-mode. By introducing aggregate
function for the reader-to-server communication, the communication cost is
reduced. We also discuss different possible applications of our protocols. Our
protocols thus capture more security properties and more efficiency than
YA-TRAP*. Finally, we show that our protocols can be implemented using the
current standard low-cost RFID infrastructures.Comment: 21 pages, Journal of Wireless Mobile Networks, Ubiquitous Computing,
and Dependable Applications (JoWUA), Vol 2, No 3, pp. 4-25, 201
Pairing-based identification schemes
We propose four different identification schemes that make use of bilinear
pairings, and prove their security under certain computational assumptions.
Each of the schemes is more efficient and/or more secure than any known
pairing-based identification scheme
A Practical Set-Membership Proof for Privacy-Preserving NFC Mobile Ticketing
To ensure the privacy of users in transport systems, researchers are working
on new protocols providing the best security guarantees while respecting
functional requirements of transport operators. In this paper, we design a
secure NFC m-ticketing protocol for public transport that preserves users'
anonymity and prevents transport operators from tracing their customers' trips.
To this end, we introduce a new practical set-membership proof that does not
require provers nor verifiers (but in a specific scenario for verifiers) to
perform pairing computations. It is therefore particularly suitable for our
(ticketing) setting where provers hold SIM/UICC cards that do not support such
costly computations. We also propose several optimizations of Boneh-Boyen type
signature schemes, which are of independent interest, increasing their
performance and efficiency during NFC transactions. Our m-ticketing protocol
offers greater flexibility compared to previous solutions as it enables the
post-payment and the off-line validation of m-tickets. By implementing a
prototype using a standard NFC SIM card, we show that it fulfils the stringent
functional requirement imposed by transport operators whilst using strong
security parameters. In particular, a validation can be completed in 184.25 ms
when the mobile is switched on, and in 266.52 ms when the mobile is switched
off or its battery is flat
Physical aspects of oracles for randomness, and Hadamard's conjecture
We analyze the physical aspects and origins of currently proposed oracles for
(absolute) randomness.Comment: 10 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1405.140
Making Existential-Unforgeable Signatures Strongly Unforgeable in the Quantum Random-Oracle Model
Strongly unforgeable signature schemes provide a more stringent security
guarantee than the standard existential unforgeability. It requires that not
only forging a signature on a new message is hard, it is infeasible as well to
produce a new signature on a message for which the adversary has seen valid
signatures before. Strongly unforgeable signatures are useful both in practice
and as a building block in many cryptographic constructions.
This work investigates a generic transformation that compiles any
existential-unforgeable scheme into a strongly unforgeable one, which was
proposed by Teranishi et al. and was proven in the classical random-oracle
model. Our main contribution is showing that the transformation also works
against quantum adversaries in the quantum random-oracle model. We develop
proof techniques such as adaptively programming a quantum random-oracle in a
new setting, which could be of independent interest. Applying the
transformation to an existential-unforgeable signature scheme due to Cash et
al., which can be shown to be quantum-secure assuming certain lattice problems
are hard for quantum computers, we get an efficient quantum-secure strongly
unforgeable signature scheme in the quantum random-oracle model.Comment: 15 pages, to appear in Proceedings TQC 201
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