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Before buying an SD memory card, I'd like to know something more about the CPRM protection, in particular:

  • Does CPRM influence the way I am supposed to access my own data? That is, does CPRM encrypt it? Could CPRM prevent me from accessing my own data?
  • Is it possible to disable or eliminate CPRM from either the memory card or the card reader?
  • Are there manufacturers selling CPRM-free SD memory cards?
  • Is there any real alternative to CPRM-protected SD memory cards beside USB flash drives?
  • Is Linux support for SD cards good?


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I haven't dealt with this but there are some related questions at the SD Assocation FAQ that might help. – fideli Apr 19 '10 at 15:54
  • I use OpenBSD and Linux primarily with SD cards and never have seen any sort of copy protection at the hardware level. I would assume that it requires certain programs. For instance if you told xTunes to write out a DRM-ripped CD to the SD card, then it may try to trigger the CPRM bits.
  • I have no idea.
  • Apparently Super Digital lacks support for CPRM according to Wikipedia
  • There is always things like CF and other such card media.
  • Very good.

Bottom line is, I think only certain programs even care about the CPRM. To be honest I don't understand how it works because it is assumingly filesystem-agnostic. How it tracks the file and such is unknown to me. In my experience I have never had any kind of problems with copy protection on SD cards and was not even aware that they had any sort of DRM technology.

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I'm on mobile so i will be brief. i know of no way in Linux to access the secure api of a sd card.

It does work on the hardware level, not fs.

Read the wikipedia entry. There are 3 modes. Open, pass (16bits) protected, read-only.

There's no protection on brute force, as far as i can tell.

If I'm not mistaken, this is what blackberry, Android and windows phones use to encrypt your sd card data.

So, answer is No. Unless you (or a rogue application on the devices you use the card in) sets up a password.

Eralz is spot on about SuperDigital

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