Classification of Signature-only Signature Models

We introduce a set of criterions for classifying signature-only signature models. By the criterions, we classify signature models into 5 basic types and 69 general classes. Theoretically, 21140 kinds of signature models can be deduced by appropriately combining different general classes. The result comprises almost existing signature models. We also contribute a lot of new signature models. Moreover, we find the three signature models, i.e., group-nominee signature, multi-nominee signature and threshold-nominee signature, are of great importance in light of our classification

Cryptanalysis and Improvement of Identity-based Proxy Multi-signature scheme

Cao-Cao’s recently proposed an identity-based proxy signature scheme and claim that the scheme is provably secure in random oracle model. In this paper we have reviewed the scheme and proven that the scheme is vulnerable to chosen message attack under the defined security model. To prevent this attack, we propose an improved version of the scheme. A Proxy multi-signature scheme allows an authorized proxy signer to sign on a message on behalf of a group of original signers

Research on ID-based Proxy Blind Signature Scheme

信息安全是信息社会急需解决的最重要问题之一，它已成为信息科学领域的一个重要的新兴学科。数字签名技术是提供认证性、完整性和不可否认性的重要技术，因而是信息安全的核心技术之一。随着对数字签名研究的不断深入，随着电子商务、电子政务的快速发展，简单模拟手写签名的一般数字签名已不能完全满足需要，研究具有特殊性质的数字签名成为数字签名的主要研究方向。 本文的主要内容是代理盲签名方案的研究。代理盲签名作为一种新型的数字签名方案，首先是由Lin等人在2000年提出。代理盲签名兼具了代理签名和盲签名的优点，正是这一特性，使得代理盲签名可以应用到电子商务、电子货币等应用领域，具有很高的实际应用价值。 基于身份...Information security is one of the most important problems in modern information society and becomes a new important subject in the information science. Digital signature, which can prove authentication, integrity and non-repudiation, is one of the key techniques of information security. As the deepening of digital signature research and the rapid development of E-commerce and E-governance, the st...学位：工学硕士院系专业：信息科学与技术学院自动化系_控制理论与控制工程学号：X200522300

Контрастивный анализ перформатива appoint и его сeрbских коpреспондентов

The collocational method enables marshalling definitions of lexemes, grammar words and categories. The article for the first time compares lexical correspondents of two languages defined in this way. The English verb appoint with its synonyms nоminate and name has been chosen and contrasted with the Serbian postaviti and (na)imenovati. The meanings of grammar words (usually prepositions) and patterns that agree with these English verbs do not always match the meanings of the corresponding grammar items in Serbian, so that these differences bring about slight differences in the definitions of these verbs, which in turn might correlate with the social and psychological differences between the speakers of the two languages.Здесь впервые сравняются методом коллокации определенные лексические корреспонденты двух языков. Избран английский глагол appoint со синонимами nominate и name, и противпоставлен с сербским поставити и (на)именовати. Сравнение глаголов appoint и поставити указывает, что предыдущий для дополнения обязательно требует сему ‘кто-то с общественной властью’, а последни ‘кто-то с общественной ролью’, в то время как ‘с властью’ является типичным признаком. Связь между ‘[быть причиной] кого-то’ и ‘кого-то с общественной властью’ сильнее в английском. Сема ‘роль общественной власти’ английских глаголов разделяется в сербском на ‘общественная роль’ и ‘категория кого-то с общественной властью’. Архаичный сербский выделяет вид в котором появляется назначенное лицо в роли. Таким образом, в сербском языке понятие общественной роли является в известной мере более подчеркнутым от понятия общественной власти, чем в английском языке

Post quantum proxy signature scheme based on the multivariate public key cryptographic signature

Proxy signature is a very useful technique which allows the original signer to delegate the signing capability to a proxy signer to perform the signing operation. It finds wide applications especially in the distributed environment where the entities such as the wireless sensors are short of computational power and needed to be convinced to the authenticity of the server. Due to less proxy signature schemes in the post-quantum cryptography aspect, in this article, we investigate the proxy signature in the post-quantum setting so that it can resist against the potential attacks from the quantum adversaries. A general multivariate public key cryptographic proxy scheme based on a multivariate public key cryptographic signature scheme is proposed, and a heuristic security proof is given for our general construction. We show that the construction can reach Existential Unforgeability under an Adaptive Chosen Message Attack with Proxy Key Exposure assuming that the underlying signature is Existential Unforgeability under an Adaptive Chosen Message Attack. We then use our general scheme to construct practical proxy signature schemes for three well-known and promising multivariate public key cryptographic signature schemes. We implement our schemes and compare with several previous constructions to show our efficiency advantage, which further indicates the potential application prospect in the distributed network environment

Secure Mobile Agent from Leakage-Resilient Proxy Signatures

A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator) to delegate its signing right to another entity (proxy) to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems

Secure Proxy Signature Schemes for Delegation of Signing Rights

A proxy signature scheme permits an entity to delegate its signing rights to another entity. These schemes have been suggested for use in numerous applications, particularly in distributed computing. But to date, no proxy signature schemes with guaranteed security have been proposed; no precise definitions or proofs of security have been provided for such schemes. In this paper, we formalize a notion of security for proxy signature schemes and present provably-secure schemes. We analyze the security of the well-known delegation-by-certificate scheme and show that after some slight but important modifications, the resulting scheme is secure, assuming the underlying standard signature scheme is secure. We then show that employment of the recently introduced aggregate signature schemes permits bandwidth and computational savings. Finally, we analyze the proxy signature scheme of Kim, Park and Won, which offers important performance benefits. We propose modifications to this scheme that preserve its efficiency, and yield a proxy signature scheme that is provably secure in the random-oracle model, under the discrete-logarithm assumption

Best Practices for the Law of the Horse: Teaching Cyberlaw and Illuminating Law Through Online Simulations

In an influential 1996 article entitled Cyberspace and the Law of the Horse, Judge Frank Easterbrook mocked cyberlaw as a subject lacking in cohesion and therefore unworthy of inclusion in the law school curriculum. Responses to Easterbrook, most notably that of Lawrence Lessig in his 1999 article The Law of the Horse: What Cyberlaw Might Teach, have taken a theoretical approach. However, this Article—also appropriating the “Law of the Horse” moniker—concludes that Easterbrook’s challenge is primarily pedagogical, requiring a response keyed to whether cyberlaw ought to be taught in law schools. The Article concludes that despite Easterbrook’s concerns, cyberlaw presents a unique opportunity for legal educators to provide capstone learning experiences through role-playing simulations that unfold on the live Internet. In fact, cyberlaw is a subject particularly well-suited to learning through techniques that immerse students in the very technologies and networks that they are studying. In light of recommendations for educational reform contained in the recent studies Best Practices for Legal Education and the Carnegie Report, the Article examines the extent to which “Cybersimulations” are an ideal way for students to learn—in a holistic and immersive manner—legal doctrine, underlying theory, lawyering skills, and professional values. The Article further explains how the simulations were developed and provides guidance on how they can be created by others. The Article concludes with a direct response to Easterbrook, arguing that cyberlaw can indeed “illuminate” the entire law

Matrilineal diversity and population history of Norwegians

Background While well known for its Viking past, Norway's population history and the influences that have shaped its genetic diversity are less well understood. This is particularly true with respect to its demography, migration patterns, and dialectal regions, despite there being curated historical records for the past several centuries. In this study, we undertook an analysis of mitochondrial DNA (mtDNA) diversity within the country to elaborate this history from a matrilineal genetic perspective. Methods We aggregated 1174 partial modern Norwegian mtDNA sequences from the published literature and subjected them to detailed statistical and phylogenetic analysis by dialectal regions and localities. We further contextualized the matrilineal ancestry of modern Norwegians with data from Mesolithic, Iron Age, and historic period populations. Results Modern Norwegian mtDNAs fell into eight West Eurasian (N, HV, JT, I, U, K, X, W), five East Eurasian (A, F, G, N11, Z), and one African (L2) haplogroups. Pairwise analysis of molecular variance (AMOVA) estimates for all Norwegians indicated they were differentiated from each other at 1.68% (p < 0.001). Norwegians within the same dialectal region also showed genetic similarities to each other, although differences between subpopulations within dialectal regions were also observed. In addition, certain mtDNA lineages in modern Norwegians were also found among prehistoric and historic period populations, suggesting some level of genetic continuity over hundreds to many thousands of years. Conclusions This analysis of mtDNA diversity provides a detailed picture of the genetic variation within Norway in light of its topography, settlement history, and historical migrations over the past several centuries.publishedVersio