Signature Size Research Articles

Improved VLR Group Signature Based on DTDH Assumption

In VLR (verifier-local revocation) group signatures, revocation messages are only sent to signature verifiers (as opposed to both signers and verifiers). Consequently there is no need to contact individual signers when some user is revoked. Since signers have no load, the VLR group signature schemes are suitable for mobile environments. To meet the requirement of speediness in mobile communication, reducing computation costs and shortening signature length are two requirements at the current research of VLR group signatures. Based on this idea, an improved version of Zhou’s VLR group signature is given. Compared with the original scheme, the improved scheme not only can achieve the same security level, but also has shorter signature size and lower computation costs.

Properties of aerosol signature size distributions in the urban environment as derived by cluster analysis

A cluster analysis algorithm was applied to reduce the amount and complexity of 30 min aerosol number size distributions in a three year data set (2006–2008) at a urban background station in Helsinki, Finland. Only after objective validity tests to determine the appropriate number of clusters, a k-means cluster algorithm was applied to extract seven characteristic size distributions from the data set. The average total number concentrations of the clustered size distributions range from 6067 cm−3 to 12,818 cm−3 with modal diameters between 5 and 193 nm. The clustered size distributions were analyzed in terms of their physical properties (shape, log-normal modes, mode diameter), temporal occurrence (e.g. time of day, season) and their relation to local meteorology.Three different types of cluster distributions being represented by either three or two log-normal modes (in only one case) were characterized at the site: four clusters that were indicative for urban-type size distributions with different influence of anthropogenic and traffic activities occurring 69% of the study time, two maritime-type distributions (29% occurrence) and one nucleation-type size distribution (2% occurrence). We were able to relate the clusters to characteristic modal diameters, different temporal occurrence on the daily and annual cycle, e.g. urban clusters that occurred year round and those that were attributed to winter daytime situations specifically. Analysis of the daily patterns clearly reveals the influence of local traffic activity on three of the four urban-type cluster size distributions. The method offers the chance for a simple kind of source apportionment by establishing signature size distributions based on the physical properties of the aerosol size spectra.

HORSIC: An efficient one-time signature scheme for wireless sensor networks

One-time signature schemes are promising candidates for broadcast authentication, which is an essential security primitive in wireless sensor networks. This paper proposes HORSIC, an efficient one-time signature scheme for broadcast authentication in wireless sensor networks. Different from previous one-time signature schemes, HORSIC can reduce the public key size and signature size simultaneously at the cost of increased overhead in key generation and signature verification.

An 18-gene blood-based IVD test for colorectal cancer early detection with high sensitivity and specificity.

3551 Background: Colorectal cancer (CRC) is often curable particularly diagnosed at early stages. Different screening strategies are in place in various counties. However, the compliance rate with current CRC screening recommendations remains poor. A simple blood-based IVD test would represent an interesting alternative. We previously reported a 100-gene signature for early detection of CRC using microarray technology. Based on this result, we have developed a new blood test with real-time PCR technology. Methods: 144 CRC cases and 153 Controls were enrolled. A total of 52 genes were selected as candidate markers to be transferred from microarray to real-time PCR. The gene expression profiles from 100 CRC cases and 100 Controls were used as a training set for signature discovery. Signature identification process was conducted by Minimum Redundancy Maximum Relevance (mRMR) feature selection method and Support Vector Machine (SVM) classification algorithm under the Leave-One-Out Cross Validation (LOOCV) framework. The optimal size of signature was determined by a stepwise inclusion selection procedure which started with one gene and repeatedly added genes one by one until all genes were included. The performance of each N-gene signature by the LOOCV was estimated and used to determine the best size of signature. Results: The gene expression profiles measured by microarray and real-time PCR technology were highly comparable and resulted in a significant correlation in term of fold change ratio between CRC cases and Controls (Pearson’s Correlation Coefficient = 0.95). An 18-gene signature was identified and validated in an independent validation set with 44 CRC cases and 53 Controls. The performance of 18-gene signature in the validation set reached 88.7% accuracy (95%CI: 0.80-0.94), 88.6% sensitivity (95%CI: 0.75-0.96), and 88.7% specificity (95%CI: 0.76-0.95). Conclusions: Our new results demonstrated the feasibility of technology transfer from microarray to real-time PCR. The blood test could be offered to individuals who are unwilling or unable to undergo colonoscopy to increase the CRC screening compliance rate. Meanwhile, its high specificity could also help to avoid unnecessary colonoscopies.

ORBITAL EFFECTS OF A TIME-DEPENDENT PIONEER-LIKE ANOMALOUS ACCELERATION

We work out the impact that the recently determined time-dependent component of the Pioneer Anomaly (PA), if interpreted as an additional exotic acceleration of gravitational origin with respect to the well-known PA-like constant one, may have on the orbital motions of some planets of the solar system. By assuming that it points towards the Sun, it turns out that both the semi-major axis a and the eccentricity e of the orbit of a test particle would experience secular variations. For Saturn and Uranus, for which modern data records cover at least one full orbital revolution, such predicted anomalies are up to 2–3 orders of magnitude larger than the present-day accuracies in empirical determinations of their orbital parameters from the usual orbit determination procedures in which the PA was not modeled. Given the predicted huge sizes of such hypothetical signatures, it is unlikely that their absence from the presently available processed data can be attributable to an "absorption" for them in the estimated parameters caused by the fact that they were not explicitly modeled. The magnitude of a constant PA-type acceleration at 9.5 au cannot be larger than 9×10-15 m s-2 according to the latest observational results for the perihelion precession of Saturn.

The use of high-resolution airborne magnetic, ASTER and Landsat 7 ETM+ images for identification of kimberlite pipes in the northwestern Free State Province, South Africa

Airborne magnetic, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat Thematic Mapper images were used for the detection of detailed exploration targets for kimberlite pipes located around the Kimberley and Boshof regions in the Northern Cape Province of South Africa. In order to achieve the objectives, the magnetic data and the satellite images were processed using various algorithms. The magnetic signatures of 25 previously known kimberlite pipes in the study area were used as a guide to identify new potential targets. Based on this approach, 30 kimberlite-like bodies were identified, of which 11 were given high ranks for detailed exploration. The ranking was based on a comparison of the strength of magnetic intensity and the size and geometry of the magnetic signatures (isolated sharp and circular high/low magnetic values), which are distinct from the magnetic response of the surrounding host rocks. The most prospective areas are located southeast of Kimberley Mine, east of Boshof and the central parts of the study area. In addition, the spectral angle mapping (SAM) method was applied to the first nine ASTER bands, and this enabled us to distinguish kimberlite indicator minerals (ilmenite, serpentine, olivine and phlogopite). The results of the SAM algorithm show that the images classified as ilmenite and phlogopite form linear patterns, which coincide with palaeo-channels in the northern part and mafic dikes in the southeastern part of the area. The thematic map derived from a classification of the image shows the presence of significant amounts of serpentine in the western part of the area around Kimberley Mine, which is consistent with the composition of the soil derived from the altered and weathered ultramafic rocks. In general, the SAM technique was successful in supplementing the identification of detailed exploration targets.

Attribute-based signature scheme with constant size signature in the standard model

In this study, the authors propose a new efficient attribute-based signature (ABS) scheme. This scheme achieves existential unforgeability against selective predicate attack and attributes signer privacy in the standard model. The signature scheme only needs three pairing operations, and the signature size is constant, regardless of the number of attributes. Compared with other existing schemes, this construction provides better efficiency in terms of the computational cost and communication cost. To the best of author's knowledge, this is the first ABS scheme that can achieve constant signature size and constant number of pairing operations. In addition, after the analysis of Wang and Chen's attribute-based ring signature scheme, the authors show that their scheme is incorrect.

Sub-Linear Size Traceable Ring Signatures without Random Oracles

Traceable ring signatures, proposed at PKC'07, are a variant of ring signatures, which allow a signer to anonymously sign a message with a tag behind a ring, i.e., a group of users chosen by the signer, unless he signs two messages with the same tag. However, if a signer signs twice on the same tag, the two signatures will be linked and the identity of the signer will be revealed when the two signed messages are different. Traceable ring signatures can be applied to anonymous write-in voting without any special voting authority and electronic coupon services. The previous traceable ring signature scheme relies on random oracles at its security and the signature size is linear in the number of ring members. This paper proposes the first secure traceable ring signature schemes without random oracles in the common reference string model. In addition, the proposed schemes have a signature size of O(√N), where N is the number of users in the ring.

Alternative statistical techniques for aiding SFRA diagnostics in transformers

In order to aid the interpretative capability of the sweep frequency response analysis (SFRA) technique used for deformation diagnostics of transformers, two new statistical indicators, viz. the t-test and comparative standard deviation (CSD) have been proposed in this study. The motivations behind suggesting the t-test are two-fold, viz. (a) the ambiguity in the results provided by some statistical parameters for borderline cases, and (b) the fact that commonly used statistical parameters require the same sample data size and spot frequencies of the SFRA signatures being compared. The CSD parameter is a logical extension of standard deviation for the comparison of two data sets. The advantages of using the proposed statistical indicators have been demonstrated through six case studies.

Joint Relay Selection and Resource Allocation for Cooperative OFDMA Network

A separable identity-based ring signature scheme has been constructed as a fundamental cryptographic primitive for protecting user privacy. Using the separability property, ring members can be selected from arbitrary domains, thereby, giving a signer a wide range of ways to control privacy. In this paper we propose a generic method to construct efficient identity-based ring signature schemes with various levels of separability. We first describe a method to efficiently construct an identity-based ring signature scheme for a single domain, in which a signer can select ring identities by choosing from identities defined only for the domain. Next, we present a generic method for linking ring signatures constructed for a single domain. Using this method, an identity-based ring signature scheme with a compact structure, supporting multiple arbitrary domains can be designed. We show that our method outperforms the best known schemes in terms of signature size and computational costs, and that the security model based on the separability of identity-based ring signatures, presented in this paper, is highly refined and effective by demonstrating the security of all of the proposed schemes, using a model with random oracles.

Lack of sufficiently strong informative features limits the potential of gene expression analysis as predictive tool for many clinical classification problems

BackgroundOur goal was to examine how various aspects of a gene signature influence the success of developing multi-gene prediction models. We inserted gene signatures into three real data sets by altering the expression level of existing probe sets. We varied the number of probe sets perturbed (signature size), the fold increase of mean probe set expression in perturbed compared to unperturbed data (signature strength) and the number of samples perturbed. Prediction models were trained to identify which cases had been perturbed. Performance was estimated using Monte-Carlo cross validation.ResultsSignature strength had the greatest influence on predictor performance. It was possible to develop almost perfect predictors with as few as 10 features if the fold difference in mean expression values were > 2 even when the spiked samples represented 10% of all samples. We also assessed the gene signature set size and strength for 9 real clinical prediction problems in six different breast cancer data sets.ConclusionsWe found sufficiently large and strong predictive signatures only for distinguishing ER-positive from ER-negative cancers, there were no strong signatures for more subtle prediction problems. Current statistical methods efficiently identify highly informative features in gene expression data if such features exist and accurate models can be built with as few as 10 highly informative features. Features can be considered highly informative if at least 2-fold expression difference exists between comparison groups but such features do not appear to be common for many clinically relevant prediction problems in human data sets.

Multicast Authentication in the Smart Grid With One-Time Signature

Multicast has been envisioned to be useful in many smart grid applications such as demand-response, wide area protection , in-substation protection and various operation and control. Since the multicast messages are related to critical control, authentication is necessary to prevent message forgery attacks. In this paper, we first identify the requirements of multicast communication and multicast authentication in the smart grid. Based on these requirements, we find that one-time signature based multicast authentication is a promising solution, due to its short authentication delay and low computation cost. However, existing one-time signatures are not designed for the smart grid and they may have high storage and bandwidth overhead. To address this problem, we propose a new one-time signature scheme which can reduce the storage cost by a factor of 8 and reduce the signature size by 40% compared with existing schemes. Thus, our scheme is more appropriate for smart grid applications where the receivers have limited storage (e.g., home appliances and field devices) or where data communication is frequent and short (e.g., phasor data). These gains are at the cost of increased computations in signature generation and/or verification and fortunately our scheme can flexibly allocate the computations between the sender and receiver based on their computing resources. We formulate the computation allocation as a nonlinear integer programming problem to minimize the signing cost under a certain verification cost and propose a heuristic solution to solve it.

Physics Based Prognostic Health Management for Thermal Barrier Coating System

Reliable prognostic of thermal barrier coating systems (TBCs) as applied to hot section engine components is a challenging task. Physics based approach is made here involving both experimental physical damage signature analysis and thermal cycle simulations. Thermally grown oxides (TGO) and the developing cracks in TBCs increase with thermal exposures. An exponential relationship is observed between the two parameters. Significant variations in size and characteristics of the damage signatures are observed depending on the four typical cycle profiles considered. In this paper, fourth order Runge-Kutta method is used for the numerical analysis of the differential equation for TGO growth analysis. Damage tolerance approach considering fracture mechanics based stress intensity factor is used to determine the crack tolerance level and remaining useful life. Our earlier fracture mechanical model for composite TBCs is modified assuming the crack to nucleate and grow within the TBC and not inside TGO. An overview of the PHM solution is presented.

Intrusion-resilient identity-based signature: Security definition and construction

Traditional identity-based signatures depend on the assumption that secret keys are absolutely secure. Once a secret key is exposed, all signatures associated with this secret key have to be reissued. Therefore, limiting the impact of key exposure in identity-based signature is an important task. In this paper, we propose to integrate the intrusion-resilient security into identity-based signatures to deal with their key exposure problem. Compared with forward-secure identity-based signatures and key-insulated identity-based signatures, our proposal can achieve higher security. The proposed scheme satisfies that signatures in any other time periods are secure even after arbitrarily many compromises of base and signer, as long as the compromises do not happen simultaneously. Furthermore, the intruder cannot generate signatures pertaining to previous time periods, even if she compromises base and signer simultaneously to get all their secret information. The scheme enjoys nice average performance. There are no cost parameters including key setup time, key extract time, base (signer) key update time, base (signer) key refresh time, signing time, verifying time, and signature size, public parameter size, base (signer) storage size having complexity more than O(log T) in terms of the total number of time periods T in this scheme. We also give the security definition of intrusion-resilient identity-based signature scheme and prove that our scheme is secure based on this security definition in the random oracle model assuming CDH problem is hard.

An efficient short certificate-based signature scheme

Certificate-based cryptography combines the merits of traditional public key infrastructure (PKI) and identity-based cryptography. It does not have the key escrow problem in identity-based cryptography, and eliminates the certificate revocation problem and third-party queries in traditional PKI. In this paper, we first refine the security model of certificate-based signatures introduced in EuroPKI’07. We then present a short certificate-based signature scheme, which is proven to be existentially unforgeable against adaptive chosen message attacks in the random oracle model. Our scheme requires only one pairing operation (and three pre-computable pairing operations) in signature generation and verification. In addition, the signature size of our scheme is only one group element. To the best of our knowledge, the signature size of our scheme is the shortest and the computational cost is the lowest when compared with other concrete certificate-based signature schemes in the literature. This makes our scheme possess strong applicability in situations with limited bandwidth and power-constrained devices.

Efficient strong designated verifier signature schemes without random oracle or with non-delegatability

Designated verifier signature (DVS) allows a signer to convince a designated verifier that a signature is generated by the signer without letting the verifier transfer the conviction to others, while the public can still tell that the signature must be generated by one of them. Strong DVS (SDVS) strengthens the latter part by restricting the public from telling whether the signature is generated by one of them or by someone else. In this paper, we propose two new SDVS schemes. Compared with existing SDVS schemes, the first new scheme has almost the same signature size and meanwhile, is proven secure in the standard model, while the existing ones are secure in the random oracle model. It has tight security reduction to the DDH assumption and the security of the underlying pseudorandom functions. Our second new scheme is the first SDVS supporting non-delegatability, the notion of which was introduced by Lipmaa, Wang and Bao in the context of DVS in ICALP 2005. The scheme is efficient and is provably secure in the random oracle model based on the discrete logarithm assumption and Gap Diffie–Hellman assumption.

Neural Network Based Indexing and Recognition of Power Quality Disturbances

Power quality (PQ) analysis has become imperative for utilities as well as for consumers due to huge cost burden of poor power quality. Accurate recognition of PQ disturbances is still a challenging task, whereas methods for its indexing are not much investigated yet. This paper expounds a system, which includes generation of unique patterns called signatures of various PQ disturbances using continuous wavelet transform (CWT) and recognition of these signatures using feed-forward neural network. It is also corroborated that the size of signatures of PQ disturbances are proportional to its magnitude, so this feature of the signature is used for indexing the level of PQ disturbance in three sub-classes’ viz. high, medium, and low. Further, the effect of number of neurons used by neural network on the performance of recognition is also analyzed. Almost 100% accuracy of recognition substantiates the effectiveness of the proposed system.

Efficient Convertible User Designating Confirmer Partially Blind Signature with Provable Security

Any one who knows the signer’s public key can verify the validity of a given signature in partially blind signature schemes. This verifying universality may be used by cheats if the signed message is sensitive or personal. To solve this problem, a new convertible user designating confirmer partially blind signature, in which only the designated confirmer (designated by the user) and the user can verify and confirm the validity of given signatures and convert given signatures into publicly verifiable ones, is proposed. Compared with Huang et al.’s scheme, the signature size is shortened about 25% and the computation quantity is reduced about 36% in the proposed scheme. Under random oracle model and intractability of Discrete Logarithm Problem the proposed scheme is provably secure.

Research on Fair E-Payment Protocol Based on Partially Blind Signature with Analysis of Scientific Material

A new partially blind signature scheme is proposed based on Schnorr blind signature scheme. Compared with the previous schemes, the proposed scheme has lower computations and shorter signature size. By conversely using the proposed partially blind signature, a fair e-payment protocol is given. An advantage of this protocol is that two participants achieve the goals of exchanging their items without intervention of a third party. The low computations and good properties of the underlying partially blind signature guarantee that the proposed protocol has needed efficiency and security.

Detecting Derivatives using Specific and Invariant Descriptors

This paper explores the detection of derivation links between texts (otherwise called plagiarism, near-duplication, revision, etc.) at the document level. We evaluate the use of textual elements implementing the ideas of specificity and invariance as well as their combination to characterize derivatives. We built a French press corpus based on Wikinews revisions to run this evaluation. We obtain performances similar to the state of the art method (n-grams overlap) while reducing the signature size and so, the processing costs. In order to ensure the verifiability and the reproducibility of our results we make our code as well as our corpus available to the community.