How to securely wipe my memory cards?

I have some compactflash and SDHC cards that I want to get rid of. However, I think I will need to securely wipe the memory cards in case someone tries to recover any images from the cards. How would I proceed to do that?

You can use one of these tools:
http://www.thefreecoun​try.com/security/secur​edelete.shtml

Or just delete / format it and overwrite it with junk data. An SD-card - unlike a harddisk which can be recovered in a laboratory up until the 7th overwrite - is easier to wipe.

formatting should do the trick.

Livinthalife wrote in post #10214461
formatting should do the trick.

just formatting won't do the trick.... there is untold file recovery softwares out there that will successfully recover every photo from a card that has "just been formatted'

you'd need to write data over all the space to be sure something wasn't recoverable, best do a few times to be sure.

Well I guess that's good to know! I thought those file recovery programs only worked if someone only used the "delete all" function.

My understanding is that deleting or formatting just marks areas of the disk free for writing rather than removing anything, so the only way to be sure is to fill the card with rubbish or completely destroy it.

SD cards, unlike CF cards, support "low-level" formatting which only the most extreme measures might be able to recover anything from. Most file or picture recovery programs will fail at a low-level formatted SD/SDHC card. For a CF card, you'd need to completely overwrite the whole card (several times) to be reasonably sure you've zapped everything.

Given the current prices for memory cards, and the file size requirements of most current cameras, if you're replacing "outgrown" cards I'd just take a hammer to them rather than waste any time trying to sell them off after sanitizing them, especially if the photos on them were ones you really don't want anyone else to be able to recover/view.

lsquare wrote in post #10214431
I have some compactflash and SDHC cards that I want to get rid of. However, I think I will need to securely wipe the memory cards in case someone tries to recover any images from the cards. How would I proceed to do that?

Grab a hammer and smash it

Personally, I'd just reformat them. Write a bunch of random data to them, i.e. dd if=/dev/urandom of=/mount/point/for/cf and reformat them again.

^ What they said. If you still want to go an extra step, you can download a free program ... CCLeaner ... it has a tool to WIPE FREE SPACE.

Go to OPTIONS > SETTINGS > SECURE DELETION > select SECURE FILE DELETION > then pick how many passes (up to 35 passes) you want

Below that, don't forget to select which drive you want to wipe. "WIPE FREE SPACE DRIVES"

Then go back to CLEANER > WINDOWS tab > at the bottom under ADVANCED, click on WIPE FREE SPACE.

If you have a Mac, you can do it directly from Disk Utility.

The only fast, sure fire way on any card is to destroy the card.

If you have a Mac, use the secure erase of the built-in "Disk Utility". You can do a single or multiple over-write of all the data which will render the card "non-recoverable" for the original photo data files.

I think you can get PC utilities which will do the same thing. If you have something like Norton Utilities, there may be something in there for that purpose. You could also copy a bunch of executable application files onto the card several times until full and that would probably do a pretty good job of eradicating the photo files. The main point is to be sure new DATA is written throughout the card, not just cleaning up the directory structure with a format.

-howard