21,426 research outputs found
InternalBlue - Bluetooth Binary Patching and Experimentation Framework
Bluetooth is one of the most established technologies for short range digital
wireless data transmission. With the advent of wearables and the Internet of
Things (IoT), Bluetooth has again gained importance, which makes security
research and protocol optimizations imperative. Surprisingly, there is a lack
of openly available tools and experimental platforms to scrutinize Bluetooth.
In particular, system aspects and close to hardware protocol layers are mostly
uncovered.
We reverse engineer multiple Broadcom Bluetooth chipsets that are widespread
in off-the-shelf devices. Thus, we offer deep insights into the internal
architecture of a popular commercial family of Bluetooth controllers used in
smartphones, wearables, and IoT platforms. Reverse engineered functions can
then be altered with our InternalBlue Python framework---outperforming
evaluation kits, which are limited to documented and vendor-defined functions.
The modified Bluetooth stack remains fully functional and high-performance.
Hence, it provides a portable low-cost research platform.
InternalBlue is a versatile framework and we demonstrate its abilities by
implementing tests and demos for known Bluetooth vulnerabilities. Moreover, we
discover a novel critical security issue affecting a large selection of
Broadcom chipsets that allows executing code within the attacked Bluetooth
firmware. We further show how to use our framework to fix bugs in chipsets out
of vendor support and how to add new security features to Bluetooth firmware
Complexity Hierarchies and Higher-order Cons-free Term Rewriting
Constructor rewriting systems are said to be cons-free if, roughly,
constructor terms in the right-hand sides of rules are subterms of the
left-hand sides; the computational intuition is that rules cannot build new
data structures. In programming language research, cons-free languages have
been used to characterize hierarchies of computational complexity classes; in
term rewriting, cons-free first-order TRSs have been used to characterize the
class PTIME.
We investigate cons-free higher-order term rewriting systems, the complexity
classes they characterize, and how these depend on the type order of the
systems. We prove that, for every K 1, left-linear cons-free systems
with type order K characterize ETIME if unrestricted evaluation is used
(i.e., the system does not have a fixed reduction strategy).
The main difference with prior work in implicit complexity is that (i) our
results hold for non-orthogonal term rewriting systems with no assumptions on
reduction strategy, (ii) we consequently obtain much larger classes for each
type order (ETIME versus EXPTIME), and (iii) results for cons-free
term rewriting systems have previously only been obtained for K = 1, and with
additional syntactic restrictions besides cons-freeness and left-linearity.
Our results are among the first implicit characterizations of the hierarchy E
= ETIME ETIME ... Our work confirms prior
results that having full non-determinism (via overlapping rules) does not
directly allow for characterization of non-deterministic complexity classes
like NE. We also show that non-determinism makes the classes characterized
highly sensitive to minor syntactic changes like admitting product types or
non-left-linear rules.Comment: extended version of a paper submitted to FSCD 2016. arXiv admin note:
substantial text overlap with arXiv:1604.0893
Still Wrong Use of Pairings in Cryptography
Several pairing-based cryptographic protocols are recently proposed with a
wide variety of new novel applications including the ones in emerging
technologies like cloud computing, internet of things (IoT), e-health systems
and wearable technologies. There have been however a wide range of incorrect
use of these primitives. The paper of Galbraith, Paterson, and Smart (2006)
pointed out most of the issues related to the incorrect use of pairing-based
cryptography. However, we noticed that some recently proposed applications
still do not use these primitives correctly. This leads to unrealizable,
insecure or too inefficient designs of pairing-based protocols. We observed
that one reason is not being aware of the recent advancements on solving the
discrete logarithm problems in some groups. The main purpose of this article is
to give an understandable, informative, and the most up-to-date criteria for
the correct use of pairing-based cryptography. We thereby deliberately avoid
most of the technical details and rather give special emphasis on the
importance of the correct use of bilinear maps by realizing secure
cryptographic protocols. We list a collection of some recent papers having
wrong security assumptions or realizability/efficiency issues. Finally, we give
a compact and an up-to-date recipe of the correct use of pairings.Comment: 25 page
The Interlace Polynomial
In this paper, we survey results regarding the interlace polynomial of a
graph, connections to such graph polynomials as the Martin and Tutte
polynomials, and generalizations to the realms of isotropic systems and
delta-matroids.Comment: 18 pages, 5 figures, to appear as a chapter in: Graph Polynomials,
edited by M. Dehmer et al., CRC Press/Taylor & Francis Group, LL
An applicative theory for FPH
In this paper we introduce an applicative theory which characterizes the
polynomial hierarchy of time.Comment: In Proceedings CL&C 2010, arXiv:1101.520
Zero Temperature Properties of RNA Secondary Structures
We analyze different microscopic RNA models at zero temperature. We discuss
both the most simple model, that suffers a large degeneracy of the ground
state, and models in which the degeneracy has been remove, in a more or less
severe manner. We calculate low-energy density of states using a coupling
perturbing method, where the ground state of a modified Hamiltonian, that
repels the original ground state, is determined. We evaluate scaling exponents
starting from measurements of overlaps and energy differences. In the case of
models without accidental degeneracy of the ground state we are able to clearly
establish the existence of a glassy phase with .Comment: 20 pages including 9 eps figure
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