Workshop "Netz- und Service-Infrastrukturen" Hat Bayes eine Chance? Seit einigen Monaten oder Jahren werden verstärkt Bayes-Filter eingesetzt, um die Nutz-E-Mail ("`Ham"') vom unerwünschten "`Spam"' zu trennen. Diese stoßen jedoch leicht an ihre Grenzen. In einem zweiten Abschnitt wird ein Filtertest der Zeitschrift c't genauer analysiert.

Diese Arbeit zeigt ausgehend von einer Darstellung der theoretischen Grundlagen automatischer Textklassifikation, dass die aus der Statistical Learning Theory stammenden Support Vector Machines geeignet sind, zu einer präziseren Erkennung unerwünschter E-Mail-Werbung beizutragen. In einer Testumgebung mit einem Corpus von 20 000 E-Mails wurden Testläufe verschiedene Parameter der Vorverarbeitung und der Support Vector Machine automatisch evaluiert und grafisch visualisiert. Aufbauend darauf wird eine Erweiterung für die Open-Source-Software SpamAssassin beschrieben, die die vorhandenen Klassifikationsmechanismen um eine Klassifikation per Support Vector Machine erweitert.

Informationen des Universitätsrechenzentrums:Neuer Dienst: WXPSelfAdmin - Management von WXP-Rechnern mit lokalen Admin-Rechten Aufbau eines Storage Area Networks (SAN) Software in den Computerpools Was tun gegen Spam? Software-News: Neue Software-Handbücher, CATIA, Docolog Kurzinformationen: X-WiN-Anschluss mit 2Gbit/s, Umstellung der OpenSSH-Version

<p>Validerat; 20140619 (global_studentproject_submitter)</p>

Tesis por compendio / [EN] Abstract The detection of false or true opinions about a product or service has become nowadays a very important problem. Recent studies show that up to 80% of people have changed their final decision on the basis of opinions checked on the web. Some of these opinions may be false, positive in order to promote a product/service or negative to discredit it. To help solving this problem in this thesis is proposed a new method for detection of false opinions, called PU-Learning*, which increases the precision by an iterative algorithm. It also solves the problem of lack of labeled opinions. To operate the method proposed only a small set of opinions labeled as positive and another large set of opinions unlabeled are needed. From this last set, missing negative opinions are extracted and used to achieve a two classes binary classification. This scenario has become a very common situation in the available corpora. As a second contribution, we propose a representation based on n-grams of characters. This representation has the advantage of capturing both the content and the writing style, allowing for improving the effectiveness of the proposed method for the detection of false opinions. The experimental evaluation of the method was carried out by conducting three experiments classification of opinions, using two different collections. The results obtained in each experiment allow seeing the effectiveness of proposed method as well as differences between the use of several types of attributes. Because the veracity or falsity of the reviews expressed by users becomes a very important parameter in decision making, the method presented here, can be used in any corpus where you have the above characteristics. / [ES] Resumen La detección de opiniones falsas o verdaderas acerca de un producto o servicio, se ha convertido en un problema muy relevante de nuestra 'época. Según estudios recientes hasta el 80% de las personas han cambiado su decisión final basados en las opiniones revisadas en la web. Algunas de estas opiniones pueden ser falsas positivas, con la finalidad de promover un producto, o falsas negativas para desacreditarlo. Para ayudar a resolver este problema se propone en esta tesis un nuevo método para la detección de opiniones falsas, llamado PU-Learning modificado. Este método aumenta la precisión mediante un algoritmo iterativo y resuelve el problema de la falta de opiniones etiquetadas. Para el funcionamiento del método propuesto se utilizan un conjunto pequeño de opiniones etiquetadas como falsas y otro conjunto grande de opiniones no etiquetadas, del cual se extraen las opiniones faltantes y así lograr una clasificación de dos clases. Este tipo de escenario se ha convertido en una situación muy común en los corpus de opiniones disponibles. Como una segunda contribución se propone una representación basada en n-gramas de caracteres. Esta representación tiene la ventaja de capturar tanto elementos de contenido como del estilo de escritura, permitiendo con ello mejorar la efectividad del método propuesto en la detección de opiniones falsas. La evaluación experimental del método se llevó a cabo mediante tres experimentos de clasificación de opiniones utilizando dos colecciones diferentes. Los resultados obtenidos en cada experimento permiten ver la efectividad del método propuesto así como también las diferencias entre la utilización de varios tipos de atributos. Dado que la falsedad o veracidad de las opiniones vertidas por los usuarios, se convierte en un parámetro muy importante en la toma de decisiones, el método que aquí se presenta, puede ser utilizado en cualquier corpus donde se tengan las características mencionadas antes. / [CA] Resum La detecció d'opinions falses o vertaderes al voltant d'un producte o servei s'ha convertit en un problema força rellevant de la nostra època. Segons estudis recents, fins el 80\% de les persones han canviat la seua decisió final en base a les opinions revisades en la web. Algunes d'aquestes opinions poden ser falses positives, amb la finalitat de promoure un producte, o falses negatives per tal de desacreditarlo. Per a ajudar a resoldre aquest problema es proposa en aquesta tesi un nou mètode de detecció d'opinions falses, anomenat PU-Learning*. Aquest mètode augmenta la precisió mitjançant un algoritme iteratiu i resol el problema de la falta d'opinions etiquetades. Per al funcionament del mètode proposat, s'utilitzen un conjunt reduït d'opinions etiquetades com a falses i un altre conjunt gran d'opinions no etiquetades, del qual se n'extrauen les opinions que faltaven i, així, aconseguir una classificació de dues classes. Aquest tipus d'escenari s'ha convertit en una situació molt comuna en els corpus d'opinions de què es disposa. Com una segona contribució es proposa una representació basada en n-gramas de caràcters. Aquesta representació té l'avantatge de capturar tant elements de contingut com a d'estil d'escriptura, permetent amb això millorar l'efectivitat del mètode proposat en la detecció d'opinions falses. L'avaluació experimental del mètode es va dur a terme mitjançant tres experiments de classificació d'opinions utilitzant dues coleccions diferents. Els resultats obtingut en cada experiment permeten veure l'efectivitat del mètode proposat, així com també les diferències entre la utilització de varis tipus d'atributs. Ja que la falsedat o veracitat de les opinions vessades pels usuaris es converteix en un paràmetre molt important en la presa de decisions, el mètode que ací es presenta pot ser utilitzat en qualsevol corpus on es troben les característiques abans esmentades. / Hernández Fusilier, D. (2016). Detección de opinion spam usando PU-learning [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61990 / Compendio

In the context of the Internet, spam generally refers to unsolicited and unwanted electronic messages, usually transmitted to a large number of recipients. The problem with spam is that almost all of the related costs are shifted onto the recipients, and many of the messages contain objectionable content. Spam has become a significant problem for network administrators, businesses and individual Internet users that threatens to undermine the usefulness of e-mail. Globally, spam spiralled to account for over 60% of all e-mail near the end of 2004. It is a problem that costs the global economy billions of dollars a year in lost productivity, anti-spam measures and computer resources. It has forced governments to enact legislation against the problem and it has prompted the development of numerous technical countermeasures. Spam can only be defeated by a combination of legal measures, informal measures (including self regulation and social norms), technical measures and consumer education. Because spam is a relatively recent and evolving problem, the application of various common law mechanisms are explored, including the law of privacy and the law of nuisance. Various constitutional concerns may also arise in the context of spam, and the right to freedom of expression must be balanced against other competing rights and values, including the right to privacy. Comparative legislation is examined, because it is important to recognise trends in spam legislation in other jurisdictions so as to ensure a measure of interoperability with those laws. The practical difficulties in identifying spammers, and the lack of jurisdiction over offshore offenders affect the practical implementation of the current protection offered by the ECT Act. In conclusion, this thesis identifies the need for direct anti-spam legislation in South Africa, and suggests various clauses that will need to be catered for in the legislation. It is submitted that "opt-in" legislation should be preferred over "opt-out" legislation. It is further submitted that a definition of spam should be based on the volume and indiscriminate nature of the e-mail, and not only on whether the communication was commercial. Therefore, a definition of bulk unsolicited e-mail is proposed. / Criminal & Procedural Law / LLD

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur "Rechnernetze und verteilte Systeme" der Fakultaet fuer Informatik der TU Chemnitz. Workshop-Thema: Mobilitaet

In the context of the Internet, spam generally refers to unsolicited and unwanted electronic messages, usually transmitted to a large number of recipients. The problem with spam is that almost all of the related costs are shifted onto the recipients, and many of the messages contain objectionable content. Spam has become a significant problem for network administrators, businesses and individual Internet users that threatens to undermine the usefulness of e-mail. Globally, spam spiralled to account for over 60% of all e-mail near the end of 2004. It is a problem that costs the global economy billions of dollars a year in lost productivity, anti-spam measures and computer resources. It has forced governments to enact legislation against the problem and it has prompted the development of numerous technical countermeasures. Spam can only be defeated by a combination of legal measures, informal measures (including self regulation and social norms), technical measures and consumer education. Because spam is a relatively recent and evolving problem, the application of various common law mechanisms are explored, including the law of privacy and the law of nuisance. Various constitutional concerns may also arise in the context of spam, and the right to freedom of expression must be balanced against other competing rights and values, including the right to privacy. Comparative legislation is examined, because it is important to recognise trends in spam legislation in other jurisdictions so as to ensure a measure of interoperability with those laws. The practical difficulties in identifying spammers, and the lack of jurisdiction over offshore offenders affect the practical implementation of the current protection offered by the ECT Act. In conclusion, this thesis identifies the need for direct anti-spam legislation in South Africa, and suggests various clauses that will need to be catered for in the legislation. It is submitted that "opt-in" legislation should be preferred over "opt-out" legislation. It is further submitted that a definition of spam should be based on the volume and indiscriminate nature of the e-mail, and not only on whether the communication was commercial. Therefore, a definition of bulk unsolicited e-mail is proposed. / Criminal and Procedural Law / LLD

The practice of spamming (sending unsolicited electronic communications) has been dubbed “the scourge of the 21st century” affecting different stakeholders. This practice is also credited for not only disrupting electronic communications but also, it overloads electronic systems and creates unnecessary costs for those affected than the ones responsible for sending such communications. In trying to address this issue nations have implemented anti-spam laws to combat the scourge. South Africa not lagging behind, has put in place anti-spam provisions to deal with the scourge. The anti-spam provisions are scattered in pieces of legislation dealing with diverse issues including: consumer protection; direct marketing; credit laws; and electronic transactions and communications. In addition to these provisions, an Amendment Bill to one of these laws and two Bills covering cybercrimes and cyber-security issues have been published. In this thesis, a question is asked on whether the current fragmented anti-spam provisions are adequate in protecting consumers. Whether the overlaps between these pieces of legislation are competent to deal with the ever increasing threats on electronic communications at large. Finally, the question as to whether a multi-faceted approach, which includes a Model Law on spam would be a suitable starting point setting out requirements for the sending of unsolicited electronic communications can be sufficient in protecting consumers. And as spam is not only a national but also a global problem, South Africa needs to look at the option of entering into mutual agreements with other countries and organisations in order to combat spam at a global level. / Mercantile Law / LL. D.

本研究主要在探討大型企業的資訊安全案例。在二十一世紀的今天，資訊系統及電腦資產對組織的成功更加重要，所以務必防止它們遭受遺失、竄改或毀滅的風險。資訊安全是保護資料、資訊遭受意外或有意的誤用的一種過程，不論是被組織內或組織外的人，包括員工、外包的顧問或網路上的駭客。資訊安全是組織中很策略的一環，不光是也不應是資訊部門一己的責任。 依據Datamonitor的估計，美國企業一年在資訊安全漏洞上至少損失美金一百五十億元。根據電腦安全學院（Computer Security Institute, CSI）及聯邦調查局（Federal Bureau of Intelligence, FBI）2004年的問卷調查顯示百分之四十九的企業曾發生個人電腦失竊的案例。依據IronPort的估計，一年前每年約有三百億封垃圾郵件，現在則激增至五百五十億封垃圾郵件。時至今日，對於資訊安全的主要威脅不是來自於組織外的駭客、病毒或蠕蟲，而是組織內的個人。不論組織內的個人是有意或無意地違反資訊安全的政策和規定，其後果可能相當嚴重，小至組織形象受損、業務損失，大至官司纏身或巨額罰款。 根據紐約時報2006年的報導：臺灣的高科技公司佔有全球半導體晶圓專工產業百分之七十的市佔率，百分之四十的半導體封裝市場，百分之五十的半導體測試市場，百分之八十的電腦主機板市場，百分之七十二的筆記本電腦代工市場，百分之六十八的LCD螢幕市場。我們如何繼續保持在全球市場上的領先地位？我們仍然得繼續在研究發展、生產製造及全球運籌上加碼投資。然而，在全球經濟之下，如何透過執行一套安全的、全球的及穩定的資訊網路及基礎架構以提供客戶更好的服務更是必要的。 對每一位資訊長或資安長而言，資訊安全永遠是他最關心的前三大議題之一。資訊安全當然是說比做容易，正確導入與永續執行才是根本。花錢購買資訊安全設備是相對簡單的。知道要保護什麼，如何保護以及要控制什麼就沒有那麼簡單了。在真實的商業世界裡，基於家醜不外揚，鮮有公司願意分享或公佈它資訊安全上的弱點及缺點。本論文的主要目的有二：一是研究業界最新的資訊安全標準及資訊安全供應商的看法，例如： 1. 國際標準組織（International Standard Organization, ISO）17799。 2. 英國標準組織（British Standard Institute, BS）7799。 3. 國際商業機器股份有限公司（International Business Machines, IBM）的資訊安全計劃。 4. 惠普股份有限公司（HP）及Information Security System公司的資訊安全稽核機制。 5. 微軟股份有限公司（Microsoft）。 二是提供一些真實的成功案例以提供給其他有興趣的組織作為參考。從結論發現，我們可藉由改善核心業務流程，去建造新的資訊安全系統，去運營一個可長治久安的實體與虛擬的環境，並強化公司的知識管理及傳承 / In the twenty-first century, information system and computing assets are more critical to organization’s success, and as a result, must be protected from loss, modification or destruction. Information security is the process of protecting data / information from accidental or intentional misuse by person inside or outside of an organization, including employee, consultants, and hackers. Information security is a strategic part of an organization, not just the issue of Management Information System, MIS, or Information Technology, IT, department. According to “Datamonitor”, US$ 15 billion, at least, cost of information security breaches to United States businesses in one year. From the survey of Computer Security Institute, CSI, and Federal Bureau of Intelligence, FBI, in 2004, 49% of companies experienced notebook Personal Computer theft. According to IronPort, there are 55 billion spam e-mail per year right now, compared with 30 billion spam e-mail yearly. Today, the largest threat to information security is not the typical hacker, virus or worm, but the corporate insider. Whether insiders violate data security policies in advertently or with maliciously, the result can expose the company to public embarrassment, lost business, costly lawsuit, and regulatory fines. Taiwanese high-technology companies have 70% market share of worldwide semiconductor foundry business, 40% share of semiconductor package segment, 50% share of semiconductor testing, 80% of computer motherboard, 72% share of notebook PC, 68% of LCD monitor --- New York Times, 2006. How can we keep maintaining the leading positions around the globe? To invest in R&D, manufacturing, and global logistics is key. However, how to implement a secure, global and reliable IT network and infrastructure to server customers better is a must under current global economy. To every Chief Information Officer, CIO, or Chief Security Officer, CSO, Information security is always one of the top 3 to-do list. Information security is easy to talk about. But, implementations and executions are where talk must turn into action. Purchasing security device is easy. Knowing how and what to protect ad what controls to put in place is a bit more difficult. In the real commercial world, no one or company would like to share or release its weakness to the public. The objective of this thesis is to study most updated information security industry standard and information security suppliers’ view, like: 1. International Standard Organization, ISO, 17799. 2. British Standard Institute’s BS 7799. 3. IBM’s Information Security Program, ISP. 4. HP & Information Security Systems’ Information Security Audit Mechanism, ISAM. 5. Microsoft Also to provide a real successful case / framework for other companies to ensure a consistent, enterprise-wide information security focus is maintained across organization boundaries. In conclusion, this information security study proposes to transfer core business process, to build information security new applications, to run a scalable, available, secure environment, and to leverage firms’ knowledge and information.