Archive for the ‘Useful Applications’ Category
The Onion Router (TOR) network is intended to help protect the privacy of Internet users and promote greater freedom of expression online. Tor is a system of volunteer servers that acts as a buffer between Internet users and the resources they connect to. If you connect as a Tor client, your online access is channeled through this buffer before it reaches the general Internet. To understand clearly how Tor functions, you must first have a good idea of what proxy servers are, and of the role they play during network transmissions.
A proxy server acts as a middleman between a client computer and the target server or resource it is accessing. As such, proxies can be configured to log user activity and restrict Internet access; for example, by blocking certain websites or protocols. However, proxies can also help protect the client user’s privacy because the target server is only aware that it is communicating with the proxy, not with the client. For example, if you connect to a web proxy and then load a website, the site is only aware that it is being accessed by the proxy and it has no knowledge of your computer and IP address. The illustration below depicts network data flow when a proxy is deployed. Resources within the Internet icon (such as web servers) are only aware of the proxy server, not of the three clients behind it.
Now what if instead of using a single proxy server, you could connect to a network of them for increased bandwidth and availability? And what if you could encrypt your communication sessions for increased confidentiality? Using Tor, you can.
BitTorrent is not an application you install; it is a network protocol that facilitates decentralized (or distributed) file sharing over the Internet. In this way it is similar to the functionality provided by traditional peer-to-peer (P2P) applications like Napster in the 1990’s, Kazaa, and Limewire. However, BitTorrent differs fundamentally from these older P2P sharing applications because it introduces components such as BitTorrent websites, torrents, trackers, seeders, and leeches (definitions below).
BitTorrent is also unique in how it efficiently uses bandwidth to achieve high data transfer rates. If the file you want is available from multiple hosts, BitTorrent establishes connections with them and downloads chunks of the file simultaneously. Therefore you trade one large, multimegabyte or multigigabyte download for several individual downloads, each of which is handling a much smaller sized data transfer. Additionally BitTorrent allows you to share these parts of a file even if the file itself isn’t fully downloaded on your end.
Image source: Threestory Studio
Going further, the BitTorrent protocol is designed to ensure that its users share (upload) as much as they take (download). This feature is known as tit-for-tat and is meant to prevent users from downloading without uploading. In fact, BitTorrent tries to reward its generous users like so: the more files you share with others, the faster your downloads are. Obviously the number of users sharing the file you want will also play a role in determining download speed.
A situation may arise when you want to completely wipe the data from a hard drive. You may be selling or giving someone your old drive, or perhaps you just want to dispose of one in the trash. Other times your Windows installation could be crawling with malware and you want to completely erase it. Maybe you suspect your drive will soon be forcibly confiscated. In these cases you should obviously be concerned about other individuals accessing your files, even the files that you have “deleted”. For times likes these, Ben Rothke makes the case for secure data destruction in his article ‘Why Information Must Be Destroyed’.
When you want to achieve total data destruction on a drive, a tool like Darik’s Boot and Nuke (DBAN) can save the day. Even though physical destruction is the safest bet, utilities like DBAN are the next best choice. According to Wikipedia, DBAN “is designed to securely erase a hard disk until data is permanently removed and no longer recoverable, which is achieved by overwriting the data with pseudorandom numbers generated by Mersenne twister or ISAAC”.
Version 2.2.7 was released in September 2012. DBAN software is available from SourceForge.
The Offline NT Password & Registry Editor is a small Linux boot disk that you can use to change or delete Windows passwords outside of the Windows OS environment for local accounts. This can be useful if you forget your Windows password or the password belonging to the Administrator account. This utility can enable you to change or delete passwords, but it cannot tell you what the password for an account actually is. As such it is not appropriate to label Offline NT Password & Registry Editor as a ‘password recovery tool’; it’s a password editor, just like the name says.
It is compatible with Windows 3.x, Windows 95/98/ME, Windows NT, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows 7, and Windows Server 2008.
Please note that the Offline NT Password & Registry Editor (‘Offline’) home page states: “If password is reset on users that have EFS encrypted files, and the system is XP or newer, all encrypted files for that user will be UNREADABLE and cannot be recovered unless you remember the old password again“.
Also note that Offline cannot be used to change or reset Active Directory passwords.
Offline’s versioning is done using release dates. The version used in this tutorial is 110511 (for 11 May 2011).
How to use it
First, download the installation ‘cd******.zip’ file from the website above and extract it locally. Burn the resulting .iso file to a CD-ROM. If you plan to boot to a USB drive, download the ‘usb********.zip’ file and extract its contents to the drive.
Second, insert the CD or USB drive into the computer and reboot it. Before the Windows OS loads (while the manufacturer’s screen is briefly displayed), hit the appropriate key (usually one of the twelve ‘F’ keys) to enter the boot device manager where you can specify a device to boot to (overriding the default device, which is almost always
C:\ on the internal hard drive).
Your computer will load the contents of the Offline CD or USB drive. When it is finished you will be prompted as follows.