11,102 research outputs found
Post-quantum cryptographic hardware primitives
The development and implementation of post-quantum cryptosystems have become a pressing issue in the design of secure computing systems, as general quantum computers have become more feasible in the last two years. In this work, we introduce a set of hardware post-quantum cryptographic primitives (PCPs) consisting of four frequently used security components, i.e., public-key cryptosystem (PKC), key exchange (KEX), oblivious transfer (OT), and zero-knowledge proof (ZKP). In addition, we design a high speed polynomial multiplier to accelerate these primitives. These primitives will aid researchers and designers in constructing quantum-proof secure computing systems in the post-quantum era.Published versio
From usability to secure computing and back again
Secure multi-party computation (MPC) allows multiple parties
to jointly compute the output of a function while preserving
the privacy of any individual party’s inputs to that function.
As MPC protocols transition from research prototypes to realworld
applications, the usability of MPC-enabled applications
is increasingly critical to their successful deployment and
widespread adoption. Our Web-MPC platform, designed with
a focus on usability, has been deployed for privacy-preserving
data aggregation initiatives with the City of Boston and the
Greater Boston Chamber of Commerce. After building and
deploying an initial version of the platform, we conducted a
heuristic evaluation to identify usability improvements and
implemented corresponding application enhancements. However,
it is difficult to gauge the effectiveness of these changes
within the context of real-world deployments using traditional
web analytics tools without compromising the security guarantees
of the platform. This work consists of two contributions
that address this challenge: (1) the Web-MPC platform has
been extended with the capability to collect web analytics
using existing MPC protocols, and (2) as a test of this feature
and a way to inform future work, this capability has been
leveraged to conduct a usability study comparing the two versions
ofWeb-MPC. While many efforts have focused on ways
to enhance the usability of privacy-preserving technologies,
this study serves as a model for using a privacy-preserving
data-driven approach to evaluate and enhance the usability of
privacy-preserving websites and applications deployed in realworld
scenarios. Data collected in this study yields insights
into the relationship between usability and security; these can
help inform future implementations of MPC solutions.Published versio
Converses for Secret Key Agreement and Secure Computing
We consider information theoretic secret key agreement and secure function
computation by multiple parties observing correlated data, with access to an
interactive public communication channel. Our main result is an upper bound on
the secret key length, which is derived using a reduction of binary hypothesis
testing to multiparty secret key agreement. Building on this basic result, we
derive new converses for multiparty secret key agreement. Furthermore, we
derive converse results for the oblivious transfer problem and the bit
commitment problem by relating them to secret key agreement. Finally, we derive
a necessary condition for the feasibility of secure computation by trusted
parties that seek to compute a function of their collective data, using an
interactive public communication that by itself does not give away the value of
the function. In many cases, we strengthen and improve upon previously known
converse bounds. Our results are single-shot and use only the given joint
distribution of the correlated observations. For the case when the correlated
observations consist of independent and identically distributed (in time)
sequences, we derive strong versions of previously known converses
A Shannon Approach to Secure Multi-party Computations
In secure multi-party computations (SMC), parties wish to compute a function
on their private data without revealing more information about their data than
what the function reveals. In this paper, we investigate two Shannon-type
questions on this problem. We first consider the traditional one-shot model for
SMC which does not assume a probabilistic prior on the data. In this model,
private communication and randomness are the key enablers to secure computing,
and we investigate a notion of randomness cost and capacity. We then move to a
probabilistic model for the data, and propose a Shannon model for discrete
memoryless SMC. In this model, correlations among data are the key enablers for
secure computing, and we investigate a notion of dependency which permits the
secure computation of a function. While the models and questions are general,
this paper focuses on summation functions, and relies on polar code
constructions
Post-Quantum Cryptographic Hardware Primitives
The development and implementation of post-quantum cryptosystems have become
a pressing issue in the design of secure computing systems, as general quantum
computers have become more feasible in the last two years. In this work, we
introduce a set of hardware post-quantum cryptographic primitives (PCPs)
consisting of four frequently used security components, i.e., public-key
cryptosystem (PKC), key exchange (KEX), oblivious transfer (OT), and
zero-knowledge proof (ZKP). In addition, we design a high speed polynomial
multiplier to accelerate these primitives. These primitives will aid
researchers and designers in constructing quantum-proof secure computing
systems in the post-quantum era.Comment: 2019 Boston Area Architecture Workshop (BARC'19
Byzantine Fault Tolerance for Nondeterministic Applications
All practical applications contain some degree of nondeterminism. When such
applications are replicated to achieve Byzantine fault tolerance (BFT), their
nondeterministic operations must be controlled to ensure replica consistency.
To the best of our knowledge, only the most simplistic types of replica
nondeterminism have been dealt with. Furthermore, there lacks a systematic
approach to handling common types of nondeterminism. In this paper, we propose
a classification of common types of replica nondeterminism with respect to the
requirement of achieving Byzantine fault tolerance, and describe the design and
implementation of the core mechanisms necessary to handle such nondeterminism
within a Byzantine fault tolerance framework.Comment: To appear in the proceedings of the 3rd IEEE International Symposium
on Dependable, Autonomic and Secure Computing, 200
Secure Network Function Computation for Linear Functions -- Part I: Source Security
In this paper, we put forward secure network function computation over a
directed acyclic network. In such a network, a sink node is required to compute
with zero error a target function of which the inputs are generated as source
messages at multiple source nodes, while a wiretapper, who can access any one
but not more than one wiretap set in a given collection of wiretap sets, is not
allowed to obtain any information about a security function of the source
messages. The secure computing capacity for the above model is defined as the
maximum average number of times that the target function can be securely
computed with zero error at the sink node with the given collection of wiretap
sets and security function for one use of the network. The characterization of
this capacity is in general overwhelmingly difficult. In the current paper, we
consider securely computing linear functions with a wiretapper who can
eavesdrop any subset of edges up to a certain size r, referred to as the
security level, with the security function being the identity function. We
first prove an upper bound on the secure computing capacity, which is
applicable to arbitrary network topologies and arbitrary security levels. When
the security level r is equal to 0, our upper bound reduces to the computing
capacity without security consideration. We discover the surprising fact that
for some models, there is no penalty on the secure computing capacity compared
with the computing capacity without security consideration. We further obtain
an equivalent expression of the upper bound by using a graph-theoretic
approach, and accordingly we develop an efficient approach for computing this
bound. Furthermore, we present a construction of linear function-computing
secure network codes and obtain a lower bound on the secure computing capacity
- …