Cryptanalysis on Two Certificateless Signature Schemes

Certificateless cryptography has attracted a lot of attention from the research community, due to its applicability in information security. In this paper, we analyze two recently proposed certificateless signature schemes and point out their security flaws. In particular, we demonstrate universal forgeries against these schemes with known message attacks

Cryptanalysis on two certificateless signature schemes

Certificateless cryptography [1] is a new paradigm that not only removes the inherent key escrow problem of identity based public cryptography [2] (ID-PKC for short), but also eliminates the cumbersome certificate management in traditional PKI. In CL-PKC, the actual private key of a user is comprised of two secrets: a secret value and a partial private key. The user generates a secret value by himself, while the partial private key is generated by a third party called Key Generating Center (KGC), who makes use of a system wide master key and the user’s identity information. In this way, the key escrow problem in identity-based public key cryptosystems is removed. A user’s public key is derived from his/her actual private key, identity and system parameters. It could be available to other entities by transmitting along with signatures or by placing in a public directory. Unlike the traditional PKI, there is no certificate in certificateless public key cryptography to ensure the authenticity of the entity’s public key. A number of certificateless signature schemes [3–14] have been proposed. Some of them are analysed under reasonable security models with elaborate security proofs [8, 11, 13, 14], while some others are subsequently broken due to flawed security proof or unreasonable model [3, 6–8, 12]

Preparation of Palygorskite hybrid iron oxide red pigment and its application in waterborne polyurethane composite coatings and ceramics

Palygorskite (Pal) is a kind of magnesium aluminum silicate clay mineral with a one-dimensional rod and layer chain structure. Herein, Pal hybrid iron oxide red pigment (Pal/ α -Fe _2 O _3 ) was prepared by the grinding method. Pal acted as a matrix to fix α -Fe _2 O _3 particles and influenced the performances of composite pigments by changing the particle size and distribution of α -Fe _2 O _3 . The color difference analysis showed that the color performances of composite pigments were closely related to the ratio of Pal to α -Fe _2 O _3 . Compared with the original red iron oxide pigment, the tinting strength of the composite pigment was increased by about 15%. When Pal/ α -Fe _2 O _3 was used as the red pigment for coating, it had good storage stability for waterborne coating and improved its adhesion and corrosion resistance. Pal/ α -Fe _2 O _3 composite pigments had excellent high-temperature resistance, which could increase the calcination temperature of ceramic pigments and would be beneficial for the ceramic industry. The synthetic method of Pal/ α -Fe _2 O _3 composite pigment was simple, low-cost, and environmentally friendly, and could be applied to large-scale industrial production

On security of a certificateless signcryption scheme

It would be interesting if a signcryption scheme in the standard model could be made certificateless. One of the interesting attempts is due to Liu et al. [Z. Liu, Y. Hu, X. Zhang, H. Ma, Certificateless signcryption scheme in the standard model, Information Sciences 180 (3) (2010) 452-464]. In this paper, we provide a cryptanalysis on this scheme by depicting two kinds of subtle public key replacement attacks against it. Our analysis reveals that it does not meet the basic requirements of confidentiality and non-repudiation

Dietary supplementation with fermented antarctic krill shell improved the growth performance, digestive and antioxidant capability of Macrobrachium nipponense

To investigate the effects of different levels of fermented antarctic krill shell (FAKS) on the growth performance, hemolymph biochemistry, hepatopancreatic antioxidant capacity, and digestive enzyme activities of Macrobrachium nipponense, five isonitrogenous and isoenergetic experimental diets containing different proportions of FAKS (0 %, 0.25 %, 0.5 %, 1.0 %, 2.0 %) were fed to M. nipponense for 8 weeks. The results showed the weight gain rate (WGR), specific growth rate (SGR), head-to-body ratio (H/S), and head-to-tail ratio (H/T) increased first and then decreased with higher proportions of FAKS. The FAKS1.0 group exhibited the highest values, and significantly higher than that of the FAKS0 group (P < 0.05). Compared with the control group, FAKS inclusion could increase the concentration of hemolymph albumin (ALB), and reduce the concentration of alkaline phosphatase (ALP) (P < 0.05). The concentration of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly lower in the FAKS1.0 group (P < 0.05). The hepatopancreas trypsin (TPS) concentration in the FAKS1.0 group, and the lipoprotein lipase (LPL) concentration in the FAKS0.25, FAKS0.5 and FAKS1.0 groups were significantly higher than that in other groups respectively (P < 0.05). With increasing proportions of FAKS, the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and ceruloplasmin (CP) in the hepatopancreas tended to increase and then decrease, and were significantly higher in the FAKS0.5 group than that in the FAKS0 group (P < 0.05). The concentration of malondialdehyde (MDA) in the FAKS0.25, FAKS0.5 and FAKS1.0 groups was significantly lower than that in the FAKS0 group (P < 0.05). In conclusion, adding a certain level of FAKS to the feed significantly improved the growth performance, digestive enzyme, and antioxidant enzyme activity of M. nipponense. Based on the quadratic regression curve fitting, the optimal WGR and SGR can be achieved when the proportion of dietary FAKS is 1.140 % and 1.149 %, respectively