rewrite all bytes in a file with a 0.

[RS232]

Hi to all,
i have some notes regarding to secure delete of files uisng c++, but due to lack of my knowledge i am unable to grasp it. need a bit help from pros... ;)

actually i have 3 algo of secure delete see below

Fast overwrite – rewrite all bytes in a file with a 0. no verification of written data is needed.

Single overwrite – rewrite all bytes with random data. You can choose random value and replace all bytes with it, or you can rewrite every byte with new random value.

US DoD 5200.28-STD (Personnel Security Program) –
Write 0x00 to all sectors.
Write 0x01 to all sectors.
Write random symbol to all sectors.
Verify the data written in the third pass.

looking forward for solution.

thanks

[Bazzy]

Why don't you post what you have so far and say what you have problem with?