Attribute-based Encryption (ABE) is regarded as a promising cryptographic conducting tool to guarantee data owners' direct control over their data in public cloud storage. The earlier ABE schemes involve only one authority to maintain the whole attribute set, which can bring a single-point bottleneck on both security and performance. Subsequently, some multi-authority schemes are proposed, in which multiple authorities separately maintain disjoint attribute subsets. However, the single-point bottleneck problem remains unsolved. In this paper, from another perspective, we conduct a threshold multi-authority CP-ABE access control scheme for public cloud storage, named TMACS, in which multiple authorities jointly manage a uniform attribute set. In TMACS, taking advantage of (t, n) threshold secret sharing, the master key can be shared among multiple authorities, and a legal user can generate his/her secret key by interacting with any t authorities. Security and performance analysis results show that TMACS is not only verifiable secure when less than t authorities are compromised, but also robust when no less than t authorities are alive in the system. Furthermore, by efficiently combining the traditional multi-authority scheme with TMACS, we construct a hybrid one, which satisfies the scenario of attributes coming from different authorities as well as achieving security and system-level robustness.

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A sulfhydryl monomicelles interfacial assembly strategy is presented for the synthesis of fully exposed singleatom-layer Pt clusters on 2D mesoporous TiO 2 (SAL-Pt@mTiO 2 ) nanosheets. This synthesis features the introduction of the sulfhydryl group in monomicelles to finely realize the controllable co-assembly process of Pt precursors within ordered mesostructures. The resultant SAL-Pt@mTiO 2 shows uniform SAL Pt clusters ( � 1.2 nm) anchored in ultrathin 2D nanosheets ( � 7 nm) with a high surface area (139 m 2 g À 1 ), a large pore size ( � 25 nm) and a high dispersion ( � 99 %). Moreover, this strategy is universal for the synthesis of other SAL metal clusters (Pd and Au) on 2D mTiO 2 with high exposure and accessibility. When used as a catalyst for hydrogenation of 4-nitrostyrene, the SAL-Pt@mTiO 2 shows a high catalytic activity (TOF up to 2424 h À 1 ), 100 % selectivity for 4-aminostyrene, good stability, and antiresistance to thiourea poisoning under relatively mild conditions (25 °C, 10 bar).

The LED is a new lightweight cipher, which was published in CHES 2011. This cipher could be applied in the Wireless Sensor Network to provide security. On the basis of the single byte-oriented fault model, we propose a differential fault analysis on the LED cipher. The attack could recover its 64-bit secret key by introducing 4 faulty ciphertexts, and 128-bit secret key by introducing 8 faulty ciphertexts. The results in this study will be beneficial to the analysis of the same type of other iterated lightweight ciphers.

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