No abstract

Attribute-based signature (ABS) is a promising cryptographic primitive. It allows the signer to generate a signature with attributes satisfying the predicate without leaking more information, so as to provide message authenticity in an anonymous manner. However, drawbacks concerning security and efficiency hinder its applications for authentication in mobile platforms. Here, we present F2P-ABS, an escrow-free and pairing-free attribute-based signature supporting perfect signer privacy for mobile anonymous authentication. To enhance its adaptiveness to mobile platforms, a novel key extraction is proposed so that the key escrow problem is mitigated over the single authority setting. It also helps to remarkably reduce the size of the signing key. Different from existing schemes, F2P-ABS is free from pairing operations. It performs no pairing operation for verification. Without the loss of security, we prove that F2P-ABS achieves signer privacy in perfect sense. It is also proven to guarantee existential unforgeability under corrupted and adaptive chosen predicate and message attack, which is securer than existing schemes.

Three new sorbicillinoids, including trimer trisorbicillinone E (1), acremosorbicillinoids A and B (2 and 3), and a new alkaloid acremokaloid A (4), and a new natural product 2S,3S-acetyl-β-methyltryptophan (5), were isolated from an endophytic fungus Acremonium citrinum SS-g13, which is found in Fructus mori plant root. In addition, eight known sorbicillinoids (6–13) were also obtained. The new compound structures were established using NMR, HRESIMS spectra, and reported spectroscopic data. The absolute configurations of compounds 1–5, were determined by spectroscopic analysis, Snatzke’s method, and time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) calculations. Compound 11 exhibited significant cholesterol efflux enhancing activity. A plausible biosynthesis pathway for the sorbicillinoids is discussed.

No abstract

No abstract