13,309 research outputs found
The Case for Quantum Key Distribution
Quantum key distribution (QKD) promises secure key agreement by using quantum
mechanical systems. We argue that QKD will be an important part of future
cryptographic infrastructures. It can provide long-term confidentiality for
encrypted information without reliance on computational assumptions. Although
QKD still requires authentication to prevent man-in-the-middle attacks, it can
make use of either information-theoretically secure symmetric key
authentication or computationally secure public key authentication: even when
using public key authentication, we argue that QKD still offers stronger
security than classical key agreement.Comment: 12 pages, 1 figure; to appear in proceedings of QuantumComm 2009
Workshop on Quantum and Classical Information Security; version 2 minor
content revision
Privacy-Preserving Facial Recognition Using Biometric-Capsules
Indiana University-Purdue University Indianapolis (IUPUI)In recent years, developers have used the proliferation of biometric sensors in smart devices, along with recent advances in deep learning, to implement an array of biometrics-based recognition systems. Though these systems demonstrate remarkable performance and have seen wide acceptance, they present unique and pressing security and privacy concerns. One proposed method which addresses these concerns is the elegant, fusion-based Biometric-Capsule (BC) scheme. The BC scheme is provably secure, privacy-preserving, cancellable and interoperable in its secure feature fusion design.
In this work, we demonstrate that the BC scheme is uniquely fit to secure state-of-the-art facial verification, authentication and identification systems. We compare the performance of unsecured, underlying biometrics systems to the performance of the BC-embedded systems in order to directly demonstrate the minimal effects of the privacy-preserving BC scheme on underlying system performance. Notably, we demonstrate that, when seamlessly embedded into a state-of-the-art FaceNet and ArcFace verification systems which achieve accuracies of 97.18% and 99.75% on the benchmark LFW dataset, the BC-embedded systems are able to achieve accuracies of 95.13% and 99.13% respectively. Furthermore, we also demonstrate that the BC scheme outperforms or performs as well as several other proposed secure biometric methods
Actor-network procedures: Modeling multi-factor authentication, device pairing, social interactions
As computation spreads from computers to networks of computers, and migrates
into cyberspace, it ceases to be globally programmable, but it remains
programmable indirectly: network computations cannot be controlled, but they
can be steered by local constraints on network nodes. The tasks of
"programming" global behaviors through local constraints belong to the area of
security. The "program particles" that assure that a system of local
interactions leads towards some desired global goals are called security
protocols. As computation spreads beyond cyberspace, into physical and social
spaces, new security tasks and problems arise. As networks are extended by
physical sensors and controllers, including the humans, and interlaced with
social networks, the engineering concepts and techniques of computer security
blend with the social processes of security. These new connectors for
computational and social software require a new "discipline of programming" of
global behaviors through local constraints. Since the new discipline seems to
be emerging from a combination of established models of security protocols with
older methods of procedural programming, we use the name procedures for these
new connectors, that generalize protocols. In the present paper we propose
actor-networks as a formal model of computation in heterogenous networks of
computers, humans and their devices; and we introduce Procedure Derivation
Logic (PDL) as a framework for reasoning about security in actor-networks. On
the way, we survey the guiding ideas of Protocol Derivation Logic (also PDL)
that evolved through our work in security in last 10 years. Both formalisms are
geared towards graphic reasoning and tool support. We illustrate their workings
by analysing a popular form of two-factor authentication, and a multi-channel
device pairing procedure, devised for this occasion.Comment: 32 pages, 12 figures, 3 tables; journal submission; extended
references, added discussio
EasyUC: using EasyCrypt to mechanize proofs of universally composable security
We present a methodology for using the EasyCrypt proof assistant (originally designed for mechanizing the generation of proofs of game-based security of cryptographic schemes and protocols) to mechanize proofs of security of cryptographic protocols within the universally composable (UC) security framework. This allows, for the first time, the mechanization and formal verification of the entire sequence of steps needed for proving simulation-based security in a modular way: Specifying a protocol and the desired ideal functionality; Constructing a simulator and demonstrating its validity, via reduction to hard computational problems; Invoking the universal composition operation and demonstrating that it indeed preserves security. We demonstrate our methodology on a simple example: stating and proving the security of secure message communication via a one-time pad, where the key comes from a Diffie-Hellman key-exchange, assuming ideally authenticated communication. We first put together EasyCrypt-verified proofs that: (a) the Diffie-Hellman protocol UC-realizes an ideal key-exchange functionality, assuming hardness of the Decisional Diffie-Hellman problem, and (b) one-time-pad encryption, with a key obtained using ideal key-exchange, UC-realizes an ideal secure-communication functionality. We then mechanically combine the two proofs into an EasyCrypt-verified proof that the composed protocol realizes the same ideal secure-communication functionality. Although formulating a methodology that is both sound and workable has proven to be a complex task, we are hopeful that it will prove to be the basis for mechanized UC security analyses for significantly more complex protocols and tasks.Accepted manuscrip
Computational Soundness for Dalvik Bytecode
Automatically analyzing information flow within Android applications that
rely on cryptographic operations with their computational security guarantees
imposes formidable challenges that existing approaches for understanding an
app's behavior struggle to meet. These approaches do not distinguish
cryptographic and non-cryptographic operations, and hence do not account for
cryptographic protections: f(m) is considered sensitive for a sensitive message
m irrespective of potential secrecy properties offered by a cryptographic
operation f. These approaches consequently provide a safe approximation of the
app's behavior, but they mistakenly classify a large fraction of apps as
potentially insecure and consequently yield overly pessimistic results.
In this paper, we show how cryptographic operations can be faithfully
included into existing approaches for automated app analysis. To this end, we
first show how cryptographic operations can be expressed as symbolic
abstractions within the comprehensive Dalvik bytecode language. These
abstractions are accessible to automated analysis, and they can be conveniently
added to existing app analysis tools using minor changes in their semantics.
Second, we show that our abstractions are faithful by providing the first
computational soundness result for Dalvik bytecode, i.e., the absence of
attacks against our symbolically abstracted program entails the absence of any
attacks against a suitable cryptographic program realization. We cast our
computational soundness result in the CoSP framework, which makes the result
modular and composable.Comment: Technical report for the ACM CCS 2016 conference pape
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