You can get software that will do multiple overwrites
of the hard drive with different characters, and usually this would be good enough.
But one is not likely to thoroughly overwrite
the data on a high-density diskette, which has a coercivity of about 700 Oe, because most drive heads cannot come close to the recommended 3,500 Oe.
The LF-7010 is the world's first commercially available unit to use phase-change technology to overwrite
data in one pass.
If you changed just one or several words or numbers in each of the files, the system will update only the data you changed--not overwrite
the entire file.
Panasonic Communications & Systems Company has introduced the world's first commercially available multi-function rewritable optical disc drive that uses a newly developed phase-change technology to overwrite
data in one pass, the LF-7010.
The only safe way to delete a computer file is to erase it and overwrite
it with new data several times so that no traces survive.
Several packages are available--usually for under $50--that will overwrite
any files that are sent to be deleted.
Option - The Image Overwrite
option electronically "shreds" data stored on the machine's hard disk during routine job processing.
E, Kama Sutra and MyWife, is transmitted via e-mail, and once activated, will overwrite
files on the third day of each month.
3, this highly destructive worm will overwrite
a user's files and will try to infect all shared file systems.
This worm, first detected on January 16th, 2006, had infected nearly 700,000 computers by early Monday, January 23, and includes a trigger code that will overwrite
data in several Microsoft and Adobe document formats on February 3rd, effectively destroying valuable data.