Are Secure Digital (SD) cards really that secure?

SunBow used Ask the Experts™
Soliciting opinions, comments, barbs, information, technical aspects, whatever, with respect to the zdnet article and quotes below. For more content, there'll be more points for good comments.

"For example, are Secure Digital (SD) cards really that secure? I don't see how a postage stamp-sized piece of plastic could be. "

"And I have no idea whether or not the data on an SD card is actually secure. After all, it's not like you need a password to use one",10738,2914557,00.html
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The only difference between the secure digital and the MMC cards are that the SD card has a small plastic slider that prevents the card from being written to, kinda like the write protect slider on a regular floppy disk

Well, it's a bit more than that!

Actually the SD cards are NOT designed for security of files that you place on them.   It was designed for the much hated Digital Rights Management (DRM) applications, such as ripping music CD's into MP3 files.

So, from your perspective, SD cards do not provide you with any security features at all.


interesting.                                               (listening....)
OWASP: Avoiding Hacker Tricks

Learn to build secure applications from the mindset of the hacker and avoid being exploited.

Uh... you were expecting more?  :)

In the context of an SD card the term "Secure" means "Copywrite Protection"

The web site has some good technical/FAQ stuff

The ZDNet article was obviously not well researched... as the author obviously thought that his content was supposed to be somehow secured (a commone misconception, by the way).
Sunbow, both the other comments in this string are exactley what i said, there is no difference from SD to MMC and if you are familliar with MMC cards then you should realize teh specifics, and I assume you are familliar.


graye> Uh... you were expecting more?  :)

Trying to not have expectations. Hoping for education. More is better.

> article was obviously not well researched...

Maybe researched better, who knows. One reason for doing the link, showing source needing to post some technical details, in a way that provides enough controversy (confusion) to increase hit rate. He's not all that bad I don't think. But I almost skipped it were I not bored on every problem being related to RPC/Blaster etc. Author is 'reporter' after all.

chaddupuis>  you should realize teh specifics, and I assume you are familliar.

false assumption. I look for some education, and hadn't dwelt on it much, let alone for security or what people really use them for (independent of advertisements for their potential). What they could be useful for. With enough background here in the thread, I can google up something later if needed.

         [increasing from 126 to 200 points for an appearing value to topic, point split etc. I can go more]


> I look for some education

I mean high level. Not needing to go too technical (low level) in discussion unnecessarily, only where needed to support a context. Links to technical details ok, if it comes to that
Here is specific architechture of the SD Cards:

The first line reads: The SD Memory Card has a mechanical write-protect switch so that vital data will not be lost accidently.

This document contains all you need to know about MMC cards:

Multimedia Card (MMC) – The MMC format has a considerable combination of high scalability, small dimensions, and security features. It allows two stacked flash die in one MMC to increase the capacity. It features a high performance serial interface capable of performing reads at 20 Mbits per second and writes at 2 Mbits per second

Secure Digital Flash (SD) – SD is a new format created by Toshiba, Matsushita Electric, and Sandisk. SD includes a proprietary security function in both the hardware and software. This is a necessary feature when the music industry makes the contents accessible over the internet. It is compatible to the Multimedia Card but is considered a better option with the security feature. It also supports the stack memory format.

From what I gathered, specific flaws in the MMC cards were limitations on storage space due to lack of future planning in the initial design and no way of write protecting the data. SD addresses theses issues but one other issue has not been addressed, you must be very carefu with these cards as if dropped they may lose your data, and it remains unrecoverable.


I'd like more, and had temptation to let it run the weekend to permit that audience in on this, and close to open new month. But with other things to do like fix my car, lest I get negligent, I'll split now, 350 for chaddupuis and another 150 for graye, total 500 for initial tender of 126.

If anyone does have something else to add, please feel free.


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