24,297 research outputs found
Field test of a practical secure communication network with decoy-state quantum cryptography
We present a secure network communication system that operated with
decoy-state quantum cryptography in a real-world application scenario. The full
key exchange and application protocols were performed in real time among three
nodes, in which two adjacent nodes were connected by approximate 20 km of
commercial telecom optical fiber. The generated quantum keys were immediately
employed and demonstrated for communication applications, including unbreakable
real-time voice telephone between any two of the three communication nodes, or
a broadcast from one node to the other two nodes by using one-time pad
encryption.Comment: 10 pages, 2 figures, 2 tables, typos correcte
A Survey on Homomorphic Encryption Schemes: Theory and Implementation
Legacy encryption systems depend on sharing a key (public or private) among
the peers involved in exchanging an encrypted message. However, this approach
poses privacy concerns. Especially with popular cloud services, the control
over the privacy of the sensitive data is lost. Even when the keys are not
shared, the encrypted material is shared with a third party that does not
necessarily need to access the content. Moreover, untrusted servers, providers,
and cloud operators can keep identifying elements of users long after users end
the relationship with the services. Indeed, Homomorphic Encryption (HE), a
special kind of encryption scheme, can address these concerns as it allows any
third party to operate on the encrypted data without decrypting it in advance.
Although this extremely useful feature of the HE scheme has been known for over
30 years, the first plausible and achievable Fully Homomorphic Encryption (FHE)
scheme, which allows any computable function to perform on the encrypted data,
was introduced by Craig Gentry in 2009. Even though this was a major
achievement, different implementations so far demonstrated that FHE still needs
to be improved significantly to be practical on every platform. First, we
present the basics of HE and the details of the well-known Partially
Homomorphic Encryption (PHE) and Somewhat Homomorphic Encryption (SWHE), which
are important pillars of achieving FHE. Then, the main FHE families, which have
become the base for the other follow-up FHE schemes are presented. Furthermore,
the implementations and recent improvements in Gentry-type FHE schemes are also
surveyed. Finally, further research directions are discussed. This survey is
intended to give a clear knowledge and foundation to researchers and
practitioners interested in knowing, applying, as well as extending the state
of the art HE, PHE, SWHE, and FHE systems.Comment: - Updated. (October 6, 2017) - This paper is an early draft of the
survey that is being submitted to ACM CSUR and has been uploaded to arXiv for
feedback from stakeholder
From sequence-defined macromolecules to macromolecular pin codes
Dynamic sequence-defined oligomers carrying a chemically written pin code are obtained through a strategy combining multicomponent reactions with the thermoreversible addition of 1,2,4-triazoline-3,5-diones (TADs) to indole substrates. The precision oligomers are specifically designed to be encrypted upon heating as a result of the random reshuffling of the TAD-indole covalent bonds within the backbone, thereby resulting in the scrambling of the encoded information. The encrypted pin code can eventually be decrypted following a second heating step that enables the macromolecular pin code to be deciphered using 1D electrospray ionization-mass spectrometry (ESI-MS). The herein introduced concept of encryption/decryption represents a key advancement compared with current strategies that typically use uncontrolled degradation to erase and tandem mass spectrometry (MS/MS) to analyze, decipher, and read-out chemically encrypted information. Additionally, the synthesized macromolecules are coated onto a high-value polymer material, which demonstrates their potential application as coded product tags for anti-counterfeiting purposes
Seeking Anonymity in an Internet Panopticon
Obtaining and maintaining anonymity on the Internet is challenging. The state
of the art in deployed tools, such as Tor, uses onion routing (OR) to relay
encrypted connections on a detour passing through randomly chosen relays
scattered around the Internet. Unfortunately, OR is known to be vulnerable at
least in principle to several classes of attacks for which no solution is known
or believed to be forthcoming soon. Current approaches to anonymity also appear
unable to offer accurate, principled measurement of the level or quality of
anonymity a user might obtain.
Toward this end, we offer a high-level view of the Dissent project, the first
systematic effort to build a practical anonymity system based purely on
foundations that offer measurable and formally provable anonymity properties.
Dissent builds on two key pre-existing primitives - verifiable shuffles and
dining cryptographers - but for the first time shows how to scale such
techniques to offer measurable anonymity guarantees to thousands of
participants. Further, Dissent represents the first anonymity system designed
from the ground up to incorporate some systematic countermeasure for each of
the major classes of known vulnerabilities in existing approaches, including
global traffic analysis, active attacks, and intersection attacks. Finally,
because no anonymity protocol alone can address risks such as software exploits
or accidental self-identification, we introduce WiNon, an experimental
operating system architecture to harden the uses of anonymity tools such as Tor
and Dissent against such attacks.Comment: 8 pages, 10 figure
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