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Showing posts from September, 2006

Secure Deletion of Data from Magnetic and Solid-State Memory

Secure Deletion of Data from Magnetic and Solid-State Memory `shred': Remove files more securely `shred' overwrites devices or files, to help prevent even very expensive hardware from recovering the data. Ordinarily when you remove a file (*note rm invocation::), the data is not actually destroyed. Only the index listing where the file is stored is destroyed, and the storage is made available for reuse. There are undelete utilities that will attempt to reconstruct the index and can bring the file back if the parts were not reused. On a busy system with a nearly-full drive, space can get reused in a few seconds. But there is no way to know for sure. If you have sensitive data, you may want to be sure that recovery is not possible by actually overwriting the file with non-sensitive data. The best way to remove something irretrievably is to destroy the media it's on with acid, melt it down, or the like. For cheap removable media like floppy disks, this is the preferred

Danger of 'Ctrl+C' on the Web

We do copy various data by ctrl+c for pasting elsewhere. This copied data is stored in clipboard and is accessible from the net by a combination of Javascripts and ASP. Just try this: 1) Copy any text by 'ctrl+c' 2) Click the Link: www.sourcecodesworld.com/special/clipboard.asp You will see the text you copied on the Screen which was accessed by this web page. (Check it out !!) Do not keep sensitive data (like passwords, reditcard numbers, PIN etc.) in the clipboard while surfing the web. It is extremely easy to extract the text stored in the clipboard to steal your sensitive information. Be cautious ... To avoid Clipboard Hack Problem, do the following: 1) In Internet Explorer, Go to Tools -> Internet options -> Security 2) Press Custom level. 3) In the security settings, select disable under Allow paste operations via script and click on 'OK. (Now the contents of your clipboard are safe.) It doesn't work on firefox. Happy Surfing......

Recover from rm

In order to undelete a file, you must know the following things: • On which device your file was stored • What kind of file system was used (eg. ext2, reiserFS, vfat) To find it out, type 'mount | column -t' Or echo "DEVICE DIRECTORY FS-TYPE" > tmp; mount | cut -d" " -f1,3,5 | sort >> tmp; cat tmp | column -t | sed -e "1s/.*/`tput smso`&`tput rmso`/" The output should be something like this: bash$ mount | column -t /dev/hda5 on / type ext2 (rw) proc on /proc type proc (rw) usbdevfs on /proc/bus/usb type usbdevfs (rw) devpts on /dev/pts type devpts (rw) /dev/hda1 on /mnt/windows/C type vfat (rw,noexec,nosuid,nodev) /dev/hda6 on /mnt/windows/E type vfat (rw,noexec,nosuid,nodev) /dev/hdc5 on /mnt/oldwin type vfat (rw,noexec,nosuid,nodev) Now, of which (printed) directory was the directory of your deleted file a subdirectory? E.g. if your file

Proxy server types and uses for HTTP Server

Proxy server In an enterprise that uses the Internet, a proxy server is a server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service. A proxy server is associated with or part of a gateway server that separates the enterprise network from the outside network and a firewall server that protects the enterprise network from outside intrusion. Proxy servers receive requests intended for other servers and then act to fulfill, forward, redirect, or reject the requests. Exactly which service is carried out for a particular request is based on a number of factors which include: the proxy server's capabilities, what is requested, information contained in the request, where the request came from, the intended destination, and in some cases, who sent the request. An advantage of a proxy server is that its cache can serve all users. If one or more Internet sites are frequently requested