23 research outputs found

    Peer to Peer Mobile Coupons: Adding Incentives without Sacrificing Security

    Get PDF
    Mobile commerce is flourishing today due to the advance of the mobile technology. Many conventional marketing activities are moving their ways to the mobile environment. Efficient marketing instruments such as the paper coupons and the electronic coupons are also evolving into the mobile coupons. In comparison with conventional coupons, mobile coupons are personalized and suitable for peer to peer delivery. Coupons are commonly issued by the merchants, used by the interested customers, and discarded by the uninterested receivers. Raising the redemption rate of the coupon will increase the sales of the promoted items. The raise can be accomplished by forwarding coupons from uninterested receivers to potentially interested customers. The ease-of-use exchange mechanism in mobile devices pushes the delivery in the peer to peer environment. Moreover, the characteristic of personalization inspires trust into mobile coupons. Thus, adding the incentives of coupon forwarding, such as a reward bonus, may activate the movement of stationary coupons and eventually increase the redemption rate of mobile coupons. Nevertheless, the incentives adding may bring the threats of alterations and forgery; if the adding mechanism is improperly made. Additionally, complicated security means are hindered by the limitations of storage space, computation power, and communication bandwidth of mobile devices. Therefore, we propose a scheme that uses digital signatures for verifying the incentive-added coupons and design a hash chain to detect possible forgery. The proposed scheme may increase the use of peer to peer mobile coupons without sacrificing the security

    Secure and Transferable Mobile Ticketing Using Digital Rights Managements

    Get PDF
    The increasingly matured mobile commerce enriches our daily lives. Mobile ticketing, a process that allows consumers to order, make payment, acquire, and authenticate tickets using their mobile phones, will become popular since it can be conducted from anywhere and at anytime. In addition to the convenience of use, the fabrication and distribution costs of traditional paper-tickets can be greatly reduced with mobile tickets. Many applications, such as traffic tickets, concert tickets, movie tickets, and so on, may take the advantages of mobile ticketing. Such tickets, in their paper-forms, can be transferred to anyone before use since no specific identity is recorded in these tickets. Nevertheless, current schemes restrict mobile tickets to be non-transferable because the transferring will result in the tickets being invalidated. To overcome the non-transferability problem, we use the idea of digital rights managements to separate the content and the usage-rules of mobile tickets, and propose a transferrable mobile ticketing scheme. The usage-rule, i.e. the rights object of the ticket, registers the ticket identification and a hashed number comprising an issuer’s random number and the International Mobile Equipment Identity (IMEI) of the ticket owner. The rights object is independently issued by a trusted third party. When a ticket is transferred, the issuer will be notified and he will modify the rights object with a new hash value, computed from a new random number and the IMEI of the new owner who receives the transferred ticket. Therefore, mobile tickets are secured and transferrable in our proposed mobile ticketing scheme

    Securing Mobile Access of Confidential Documents by Integrating Trusted Computing Platforms with Digital Rights Managements

    Get PDF
    The mature mobile network today empowers mobile employees to access Intranet documents via mobile devices and increases the productivity of company workers. Internal documents transmitted without encryption through the open mobile networks undoubtedly creates security holes for eavesdroppers. A common way to provide preliminary protections for an important document to be accessed outside the Intranet is to transmit the document after encryption. Such mechanisms, however, cannot assure the security of documents because the documents can be decrypted and then forwarded without protections once the ciphering keys were known. Therefore, we propose an approach to enhance the security of transmitted mobile documents, using the idea from digital rights managements. A confidential document is encrypted so that, except the targeted mobile user, none can read the confidential document without proper rights. The proposed approach utilizes the trusted computing platforms (TPM) technology to protect the rights object of a confidential document. A rights object can be as simple as a ciphering key of the document or as complicated as the usage-rules of the document. We use the public key in TPM to encrypt the rights object so that only the dedicated mobile device, i.e. the mobile user, may decrypt the rights object using the private key of the device. A malicious user can never decrypt the rights to access the transmitted document, which is encrypted. Moreover, the usage-rules in the rights object may specify whether the document can be further forwarded or be read more than once, and so on. Therefore, the proposed scheme provides maximum flexibilities for mobile employees to access confidential documents without compromising the security, in addition to the mobility and timeliness of mobile environments

    Efficient Computation of Group Skyline Queries on MapReduce

    Get PDF
    Skyline query is one of the important issues indatabase research and has been applied in diverse applicationsincluding multi-criteria decision support systems and so on. Theresponse of a skyline query eliminates unnecessary tuples andreturns only the user-interested result. Traditional skyline querypicks out the outstanding tuples, based on one-to-one recordcomparisons. Some modern applications request, beyond thesingular ones, for superior combinations of records. For example,fantasy basketball is composed of 5 players, fantasy baseball of 9players, and a hackathon of several programmers. Group skylineaims at considering all the groups comprising several records,and finding out the non-dominated ones. Because of the highcomplexity, few studies have been conducted and none has beenpresented in either distributed or parallel computing. This paperis the first study that solves the group skyline in the distributedMapReduce framework. We propose the MRGS algorithm togenerate all the combinations, compute the winners at each localnode, and find out the answer globally. We further propose theMRIGS algorithm to release the bottleneck of MRGS onunbalanced computing load of nodes. Finally, we propose theMRIGS-P algorithm to prune the impossible combinations andproduce indexed and balanced MapReduce computation.Extensive experiments with NBA datasets show that MRIGS-P is6 times faster than the MRGS algorithm

    應用於適性化數位學習系統之存取控制機制研究

    No full text
    適性化學習(Adaptive Learning)近年來成為一項熱門的研究,許多專家學者針對學習者不同的學習需求,提出多種適性化學習路徑規劃機制,給予學習者個人化的學習路徑與教材導覽,以提升學習者的學習成效與學習效率。而隨著數位學習系統被廣泛的使用於各產官學界,系統的存取控制議題即成為一項重要的研究。過去有許多專家學者為資訊系統中使用者的存取權限管理提出不同的存取控制機制,可惜的是無法完全適用於適性化數位學習系統。因此本研究在綜觀目前數位學習系統的存取控制需求與適性化學習最新研究後,以適性化數位學習系統中學習資源的存取控制問題著手,結合主體角色、教學規則與授體角色的設計方式,改善數位學習系統導入適性化學習路徑導覽後,產生的過度授權及授權規則數量過多的問題,並且針對課程編輯權限委任授權之需求,提出一套適性化數位學習系統所需之存取控制機制,不僅能有效的控管學習資源的存取、降低授權規則數量及增加資源分享性,更提升了課程活動樹設計上的彈性。In recent years, the adaptive learning becomes a hot spot topic, many various planning mechanisms of adaptive learning according to different learning styles, requirements and progress of learners are proposed to promote the learning effectiveness and efficiency of learners. Due to e-learning system is widely used in the manufacturing, official and academia, an access control in e-learning system becomes another important issue. During the past decade, researchers proposed different access control mechanisms for e-learning system to manage the users' authorizations, however, they can not be completely suited for the adaptive e-learning system. As the results, the proposed research focuses on the problems of access control in learning resources and delegations of e-learning system, not only to reduce the costs of system management but also to increase the uses of resource sharing

    Pilot Scale Production of Highly Efficacious and Stable Enterovirus 71 Vaccine Candidates

    Get PDF
    BACKGROUND: Enterovirus 71 (EV71) has caused several epidemics of hand, foot and mouth diseases (HFMD) in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial. PRINCIPAL FINDING: In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration), a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7-10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30-43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37 °C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4 °C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice, rats, rabbits, and non-human primates. CONCLUSION: These results provide valuable information supporting the current cell-based serum-free EV71 vaccine candidate going into human Phase I clinical trials

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

    Get PDF
    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Wide Host Range and Strong Lytic Activity of Staphylococcus aureus Lytic Phage Stau2▿

    No full text
    In searching for an alternative antibacterial agent against multidrug-resistant Staphylococcus aureus, we have isolated and characterized a lytic staphylophage, Stau2. It possesses a double-stranded DNA genome estimated to be about 134.5 kb and a morphology resembling that of members of the family Myoviridae. With an estimated latency period of 25 min and a burst size of 100 PFU/infected cell, propagation of Stau2 in liquid culture gave a lysate of ca. 6 × 1010 PFU/ml. It was stable at pH 5 to 13 in normal saline at room temperature for at least 4 weeks and at −85°C for more than 2 years, while 1 × 109 out of 2 × 1012 PFU/ml retained infectivity after 36 months at 4°C. Stau2 could lyse 80% of the S. aureus isolates (164/205) obtained from hospitals in Taiwan, with complete lysis of most of the isolates tested within 3 h; however, it was an S. aureus-specific phage because no lytic infection could be found in the coagulase-negative staphylococci tested. Its host range among S. aureus isolates was wider than that of polyvalent phage K (47%), which can also lyse many other staphylococcal species. Experiments with mice demonstrated that Stau2 could provide 100% protection from lethal infection when a multiplicity of infection of 10 was administered immediately after a challenge with S. aureus S23. Considering these results, Stau2 could be considered at least as a candidate for topical phage therapy or an additive in the food industry
    corecore