Cryptographic puzzles are a method of protecting against DoS attacks. The idea behind cryptographic puzzles is the following: for a client to connect to a server under attack, he must solve a mathematical puzzle. The difficulty of the puzzle will be directly proportional to the number of connections initiated by the client. Thus, a legitimate client will not notice a big difference when...
Hijacking performs the act of hijacking packages on the desired route, an attacker thus taking control of one of the communication nodes. It is one of the most elaborate types of computer attacks that can be encountered in industrial networks. As with RST and SYN flood attacks, this attack is based on TCP packet transmission that contains false values for address, port, and sequence or...
This type of attack is aimed at obtaining personal information (such as usernames, passwords, credit card details) by impersonating an entity that the user trusts. These attacks are usually done through email, e-mail, or social networking. Thus, in the case of phishing attacks, the attacker sends a message that contains a link to a web page that mimics the original page where the user trusts...
DoS (Denial of Service) or DDoS (Distributed Denial of Service) attacks are a way to make computational resources unavailable to legitimate users. Although the methods by which these attacks are made are very varied, these types of attacks are designed to make a web page or web service work heavily or not at all. A DoS attack can be defined as an attack targeting the availability of a computer or...
A sniffer is a computer program used to monitor and analyze network traffic from one network location to another. A sniffer captures each packet of information, decodes it and gives the owner the ability to view the content. If a sniffer is used by a trusted person, it is not considered a malicious application because it is used for troubleshooting and monitoring purposes, or to detect network...
SSL (Secure Sockets Layer) is an acronym that is a Netscape web protocol designed to transmit securely private documents over the Internet. To encrypt data, SSL uses a two-key cryptographic system: a public one, known by anyone, and a private, secret, known only by the recipient of the message. Several updates of this protocol have been offered, today the latest version being SSL 3.0, becoming...
A recent technique of fighting network attackers consists of stretching three types of strategies: 1. Baits: creating a unique user account with a simple password (user: guest, password: guest); any attacker who connects to this account is closely monitored. 2. Traps: Install and configure an operating system with the most common security flaws and vulnerabilities, easy to find, to catch...
Root-kits are malicious programs that give Internet attackers unlimited access to a system while hiding their presence at the same time. Rootkits, after accessing a system (usually exploiting a system vulnerability) use operating system features to avoid detection by antivirus software. Rootkit features: 1. System utilities and daemons have identical behavior to original programs. 2. Additional...
The RED algorithm is also known as Random Early Discard or Random Early Drop. This algorithm works at the router level. Congestion in computer networks must be discovered and fought from an early stage in order not to have an overloaded queue at the exit, which would eventually lead to blockage of the entire network. The goals we must have if we are confronted with a congested network are: 1. An...
Congestion of the network is a phenomenon which consists of deterioration of the quality of services caused by the overloading of network nodes, so the term is associated primarily with large networks, in which large amounts of data are being transmitted. Congestion has several causes: either the routers are not fast enough, their CPUs are too slow, and they do not manage to quit queuing queues...