The latest columns by Elena Keracheva

  • How to set the fastest Ubuntu download server

    Ubuntu uses hundreds of millions of servers worldwide to deliver updates to its global user base. The operating system will automatically choose a server based on your current location, yet the nearest server may not give you the quickest or most reliable access. This article explains how to change the Ubuntu download mirror.

  • Everything about different WiFi modes of operation

    Wireless adapters, or network interface controllers (NICs for short), are network cards with the 802.11 standards that let a machine connect to a wireless network. A station is any device that has such a card. Access points, also known as AP or hotspots, can let nearby WiFi-equipped stations access a wired network to which the access point is directly connected. The 802.11 standard defines two operating modes: infrastructure mode and ad hoc mode.

  • Everything about different types of networks: LAN, WAN, etc.

    Different types of private networks are distinguished based on their sizes (in terms of the number of machines), data transfer speeds, and reach. Private networks are networks that belong to a single organization. There are usually three categories of such networks: LAN, or local area network; MAN, or metropolitan area network; and WAN, or wide area network. There are also two other types of networks: TANs and CANs.

  • Private-key (or Secret-key) Cryptography: advantages

    Private-key encryption (also called symmetric encryption or secret-key encryption) involves using the same key for encryption and decryption. Encryption involves applying an operation (an algorithm) to the data to be encrypted using the private key to make them unintelligible. The slightest algorithm (such as an exclusive OR) can make the system nearly tamper-proof (keep in mind that there is no such thing as absolute security).

  • Introduction to Wi-Fi (802.11 or WiFi)

    The IEEE 802.11 specification (ISO/IEC 8802-11) is an international standard describing the characteristics of a wireless local area network (WLAN). The name Wi-Fi (which stands for Wireless Fidelity, sometimes incorrectly shortened to WiFi) corresponds to the name of the certification given by the Wi-Fi Alliance, formerly WECA (Wireless Ethernet Compatibility Alliance). This group ensures compatibility between hardware devices that use the 802.11 standards. Read on to learn more.