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• About the Easy dreams series
  They are an important milestone in the line of the publications of Andrews, because under its name a series started that, according to several feedbacks, served up a lot of useful information to both beginners and advanced users. The first article was published on the pages of the Linuxvilág magazine in November of 2000, and the last article so far (the 13th) in August of 2002. We hope that the series was not discontinued, it's just taking a long break. Its usage of words became rather localised by the editor of the Linuxvilág, at certain places even the authors of the articles couldn't understand the final version. Anyhow, usually we managed to agree.
• Zoltán Borbély, Péter Mátó
  2000
  Easy dreams - Part 1.
  The introduction of the series. It presents the readers the dangers waiting for them on the internet, their risks, tries to show the scale of the the necessary sense of danger. It dissolves many mistaken beliefs because of which the people have excessive or (and sadly it is the more frequent) smaller than necessary sense of danger, which leads to useless or negligent defence. A few basic form of attacks are reviewed, of which the users definitely have to know.
• Zoltán Borbély, Péter Mátó
  2000
  Easy dreams - Part 2.
  The second part henceforward deals with general questions. It is important to acknowledge that there may be errors in every program, and in almost all cases, there are errors. It has several reasons, the majority of which could be avoidable thorough planning, thoughtful and thorough design and testing. The article also mentions the development regulation criteria called Common Criteria (today already an ISO standard). The second part of the article reviews the most essential requirements of the planning of networks and computers.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 3.
  The third part pawes the way for further knowledge. Its most important topics are the review of IP, considered as the mother tongue of the internet, and TCP, UDP and ICMP building on that. This article is necessary for configuring a packet filter that is covered later, and gives useful knowledge and a more perfect understanding of the operation of higher level protocols and certain attacks.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 4.
  The first part of the article presents how it is practical to design the perimeter defence of a network, the second part introduces the general theory of packet filtering systems to the readers, and as an example it presents the realization of the defence of a home dial-up system with the help of the packet filter of the 2.2 kernel series.
• Zoltán Borbély, Mátó Péter
  2001
  Easy dreams - Part 5.
  The article deals with the low level attack forms threatening the network. It introduces the most important attack forms, such as information interception, IP address spoofing, connection hijacking and other IP level network attacks. It is worth reading for everyone who wants to create secure networks. It describes the possible defence methods in connection with certain attack forms, and the correct network settings for Linux systems.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 6.
  The defence capabilities of kernel 2.4 (Part 1.)
  The article deals with the most important network perimeter defence system of kernel 2.4, netfilter (or as some call it because of its tool: iptables). For the whole picture, it clarifies the most important concepts in connection with packet filtering and network traffic. The operation principles of stateful firewalls, network address translation (NAT) and port scan are also mentioned. After the general introduction the article explains the operation principles of netfilter, and possible conditions of filtering packets and connections are mentioned.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 7.
  The defence options of the 2.4 system core (Part 2.)
  The article continues discussing the basics of the usage of the netfilter. It describes the commands that can be executed in connection with the packets according to the rules discussed previously, then after the theoretical knowledge of the usage of the packet filter, through an example it presents how it is practical to develop a defence system.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 8.
  The article deals with the most important tools of network troubleshooting, tcpdump and the ethereal program. It tells us how it is possible to separate certain parts of network traffic for the sake of fast and efficient usage, and how the output of the programs should be interpreted. This article is an obligatory read for everyone trying to get to know the IP network from up close.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 9.
  The article deals with the interconnected problems of user authentication. Dangers occuring in connection with the storage of passwords and the most frequently used password coding algorithms are mentioned, then discusses thoughts about a very important question, the choosing of correct passwords. The second part of the article describes PAM, a widely used modular authentication system that is used to solve authentication problems on Linux (and other Unix) systems. It presents what modules PAM consists of, and how these can be configured in order to suit our aims.
• Zoltán Borbély, Péter Mátó
  2001
  Easy dreams - Part 10.
  This article is the sequel to Part 9., which is about the fine details of the usage of PAM. It introduces the modules that can be used and their more important functions in detail, giving practical examples for the proper configuration settings. The usage of modules enabling user authentication, configuring user limits, environmental settings and other modules providing useful services are also mentioned. It is also worth highlighting the pam_cracklib module among the discussed topics, which allows checking the password strength, and the pam_ldap module supporting central authentication.
• Zoltán Borbély, Péter Mátó
  2002
  Easy dreams - Part 11.
  Protocols I.
  This writing describes the operation of the network protocols of the internet's most frequently used programs from all angles. It reviews the operation of ping, traceroute, domain and ntp in details and provides assistance on how these protocols can be let through a packet filtering firewall.
• Zoltán Borbély, Péter Mátó
  2002
  Easy dreams - Part 12.
  Protocols II.
  This article is a sequel to the previous one, it deals with the most frequently used application level protocols. It describes the SMTP, POP3 and IMAP4 protocols, then it is the turn of the FTP protocol as well. This article assists with the proper configuration of the packet filter too.
• Zoltán Borbély, Péter Mátó
  2002
  Easy dreams - Part 13.
  The principles of encryption and digital signatures
  Encryption is a mystical territory for most people, as understanding the algorithms working in the background often requires very deep mathematical knowledge. This article is an introduction, which gives an insight to the basics of the encryption algorithms' operation in an easy form to the readers. Through a few early encryption methods, it introduces the theoretical principles of symmetric encryption, and the attacks carried out against encryption algorithms.