Abuse-resistant deniable encryption

Deniable encryption (DE) allows private communication over an insecure channel even under the coercion. That is, after an adversary forces communication participants to reveal their secret keys and randomness used during the communication, the message confidentiality can still be preserved. Since its introduction, a large body of studies have been made to improve the DE system in terms of efficiency, security definition and functionality, which is the focus of this paper. However, as far as we know, none of existing DE systems considers the abuse of deniability caused by malicious users, which is a crucial feature from the view of practical applications of DE. For instance, a malicious user (e.g., an employee who holds some sensitive documents and intends to sell these confidential contents for obtaining financial gain) can utilize a DE system to transmit the confidential content without the risk of being caught, which is extremely dangerous to the interests and security of his/her organization. In this paper, to mitigate this threat, we formally define the syntax and security notions of abuse-resistant deniable encryption, which restricts what users can deny. Then, we put forward a concrete construction of abuse-resistant DE scheme, and prove its security under the assumptions of indistinguishability obfuscation and one-way function. Compared with other related work, the proposed construction has advantages in terms of functionality and ciphertext rate simultaneously

Media 1: Experimental observations of thermo-optical bistability and self-pulsation in silicon microring resonators

Originally published in JOSA B on 01 February 2014 (josab-31-2-201

Optical characterization of deuterated silicon-rich nitride waveguides

Chemical vapor deposition-based growth techniques allow flexible design of CMOS-compatible materials. Here, we report the deuterated silicon-rich nitride films grown using plasma-enhanced chemical vapor deposition. The linear and nonlinear properties of the films are characterized. We compare the absorption at 1550nm wavelength region for films grown with $SiH_4$ and $SiD_4$, and experimentally confirm that the silicon-rich nitride films grown with $SiD_4$ eliminates Si-H related absorption. Waveguides fabricated on the films are further shown to possess a linear and nonlinear refractive index of 2.46 and $9.8$ X $10^{-18} m^2 W^{-1}$ respectively

Photostable pH-Sensitive Near-Infrared Aggregation-Induced Emission Luminogen for Long-Term Mitochondrial Tracking

Mitochondria are crucial in the process of oxidative metabolism and apoptosis. Their morphology is greatly associated with the development of certain diseases. For specific and long-term imaging of mitochondrial morphology, we synthesized a new mitochondria-targeted near-infrared (NIR) fluorescent probe (TPE–Xan–In) by incorporating TPE with a NIR merocyanine skeleton (Xan–In). TPE–Xan–In displayed both absorption (660 nm) and emission peaks (743 nm) in the NIR region. Moreover, it showed aggregation-induced emission properties at neutral pH and specifically illuminated mitochondria with good biocompatibility, superior photostability, and high tolerance to mitochondrial membrane potential changes. With a pH-responsive unit, hydroxyl xanthene (Xan), the probe exhibited a pH-sensitive fluorescence emission in the range of pH 4.0–7.0, which indicated its potential in long-term tracking of pH and morphology changes of mitochondria in the biomedical research studies