Design in Type-I, Run in Type-III: Fast and Scalable Bilinear-Type Conversion using Integer Programming

Bilinear-type conversion is to convert cryptographic schemes designed over symmetric groups instantiated with imperilled curves into ones that run over more secure and efficient asymmetric groups. In this paper we introduce a novel type conversion method called {\em IPConv} using 0-1 Integer Programming. Instantiated with a widely available IP solver, it instantly converts existing intricate schemes, and can process large-scale schemes that involves more than a thousand variables and hundreds of pairings. Such a quick and scalable method allows a new approach in designing cryptographic schemes over asymmetric bilinear groups. Namely, designers work without taking much care about asymmetry of computation but the converted scheme runs well in the asymmetric setting. We demonstrate the usefulness of conversion-aided design by presenting somewhat counter-intuitive examples where converted DLIN-based Groth-Sahai proofs are more compact than manually built SXDH-based proofs

Remarks on mix-network based on permutation networks

Abstract. This paper addresses the security and efficiency issues of the Mix-net based on permutation networks introduced in [1]. We first show that the original construction results in a Mix-net that yields biased permutation, so it gives some advantage to adversaries. A simple repair is provided. We then observe that one of the original schemes can be improved so that the servers and verifier enjoy more efficient computation and communication.

Efficient GF(3m) Multiplication Algorithm for eta T Pairing

The computation speed of pairing based cryptosystems is slow compared with the other public key cryptosystems even though several efficient computation algorithms have been proposed. Thus more efficient computation of the Tate pairing is an important research goal. GF(3m) multiplication in GF(36m) in the pairing algorithm is the greatest consumer of time. Past research concentrated on reducing the number of GF(3m) multiplications, for instance the Karatsuba method. In this article, we propose a new method to reduce the number of online precomputations( precomputations) in GF(3m) multiplications for the eta T pairing. The proposed algorithm reduces 18 online precomputations in GF(36m) in the eta T pairing to 4 online precomputations by reusing the intermediate products obtained in precomputation.We implement the proposed algorithm and compare the time taken by the proposed algorithm with that of the previous work. Our algorithm offers a 40% performance increase for GF(3m) multiplications in GF(36m) on an AMD 64-bit processor. Additionally, a completely new finding is obtained. The results show that the reducing the number of the multiplications in GF(36m) does not necessarily lead to a speed-up of the eta T pairing calculation

Efficient GF (3 m) Multiplication Algorithm for ηT Pairing

Abstract. The computation speed of pairing based cryptosystems is slow compared with the other public key cryptosystems even though several efficient computation algorithms have been proposed. Thus more efficient computation of the Tate pairing is an important research goal. GF (3 m) multiplication in GF (3 6m) in the pairing algorithm is the greatest consumer of time. Past research concentrated on reducing the number of GF (3 m) multiplications, for instance the Karatsuba method. In this article, we propose a new method to reduce the number of online precomputations(precomputations) in GF (3 m) multiplications for the ηT pairing. The proposed algorithm reduces 18 online precomputations in GF (3 6m) in the ηT pairing to 4 online precomputations by reusing the intermediate products obtained in precomputation. We implement the proposed algorithm and compare the time taken by the proposed algorithm with that of the previous work. Our algorithm offers a 40 % performance increase for GF (3 m) multiplications in GF (3 6m) on an AMD 64-bit processor. Additionally, a completely new finding is obtained. The results show that the reducing the number of the multiplications in GF (3 6m) does not necessarily lead to a speed-up of the ηT pairing calculation.

Privacy enhanced active RFID tag

In the coming future ubiquitous society, Radio Frequency Identification (RFID) tags will be affixed to every product and person. This technology is anticipated to be a key technology that will be utilized by various ubiquitous services where these tags will be used to identify things and people and will automatically take advantage of contextual information such as location. On the other hand, a problem is arising where the excellent tracking ability of RFID is abused and personal privacy is being violated. This paper clarifies the active tag privacy problem and proposes a method for protecting personal privacy regarding the active RFID tags. In the proposed method, reencryption technologies are used to make the tag ID variable. Since variable IDs generated from one ID are cannot be linked to one another by third parties, RFID privacy problems based on a fixed ID can be abated. Furthermore, we introduce an active tag prototype that implements the proposed method and evaluated its effectiveness

Cell-free microRNA-1246 in different body fluids as a diagnostic biomarker for esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma is a malignant tumor with unfavorable prognosis. In this study, we investigated the usefulness of microRNA (miR)-1246 detection in various body fluids as a biomarker for this disease. A total of 72 patients with esophageal squamous cell carcinoma were enrolled, and their blood, urine, and saliva samples were collected prior to treatment. Reverse transcription-polymerase chain reaction of miR-1246 was performed, and pre- and postoperative and intraday fluctuations in its expression were examined. The expression of miR-1246 in the blood and urine was significantly higher in the patients with esophageal squamous cell carcinoma than in 50 healthy control subjects. Receiver operating characteristic curves showed that the area under the curve values were 0.91 (sensitivity 91.7%, specificity 76.0%), 0.82 (sensitivity 90.3%, specificity 62.0%), and 0.80 (sensitivity 83.3%, specificity 66.0%) in the serum, urine, and saliva, respectively. A relatively high diagnostic performance of miR-1246 was observed in all samples, which was better than that of the existing biomarkers squamous cell carcinoma antigen, carcinoembryonic antigen, and cytokeratin 19 fragment. No clear correlation was observed in the levels of miR-1246 expression among the three body fluids. Postoperatively, serum samples displayed significantly decreased miR-1246 levels. Although not significant, changes in the miR-1246 levels were observed at all collection times, with large fluctuations in the saliva. Meanwhile, serum miR-1246 expression was found to be associated with the disease prognosis. The results indicate that the levels of miR-1246 in the urine, saliva, and serum are a useful biomarker for esophageal squamous cell carcinoma and support the use of urine samples instead of blood samples for noninvasive diagnosis